________ disk encryption is a technology, implemented in hardware or software, in which all data on a disk is automatically encrypted before it is stored.

Introduction / Context:
Protecting data stored on laptops, desktops and external drives is an important part of information security. One strong method is to encrypt data on the disk so that, even if the device is stolen or lost, the information cannot be read without the proper key or password. There are many ways to apply encryption, such as encrypting individual files or particular folders. However, some technologies encrypt the entire disk so that every piece of data written to it is protected. This question asks you to identify the correct term for encryption that automatically applies to all data on the disk, whether it is system data, user documents or temporary files.

Given Data / Assumptions:

• The technology can be implemented in hardware or software.
• All data is encrypted before being stored on the disk.
• The focus is on the whole disk, not just selected files or folders.
• The options use words suggesting partial or multiple encryption.
• We need to pick the phrase that best describes this full disk protection.

Concept / Approach:
When encryption is applied to the entire disk so that everything written to it is automatically encrypted, this is commonly called whole disk encryption or full disk encryption. The idea is that no unencrypted data ever resides on the storage device. Options such as half disk encryption or segmented disk encryption would imply that only part of the disk is protected, which does not match the definition. Double or triple disk encryption suggest repeated encryption rather than coverage of the full medium. Therefore, the phrase whole disk encryption is the closest match among the given options for a technology that encrypts all data before storage.

Step-by-Step Solution:
Step 1: Focus on the key phrase “all data on a disk is encrypted before storage.”Step 2: Recognise that this implies complete coverage of the disk surface, not partial or selective protection.Step 3: Review the options and note that Whole disk encryption clearly suggests complete disk coverage.Step 4: Understand that Half disk encryption would only protect part of the disk, which contradicts the stem.Step 5: Observe that Double and Triple disk encryption focus on how many times encryption might be applied, not on whether the entire disk is covered.Step 6: Choose Whole disk encryption as the term that correctly describes this type of technology.

Verification / Alternative check:
In many security guides, especially those referring to laptops, you will find references to full disk encryption solutions. These tools ensure that every file, including the operating system and temporary files, is stored in encrypted form. Users provide a key or password at boot time, and the system transparently decrypts data as it is read. While the phrase full disk encryption is more common in some texts, whole disk encryption is also used to refer to the same idea of encrypting the entire disk surface. Because the options in this question include Whole disk encryption and not Full disk encryption, the closest correct match is Whole disk encryption, and it clearly captures the requirement that all data is encrypted before storage.

Why Other Options Are Wrong:

• Half disk encryption would imply that only half of the disk is protected, leaving the rest unencrypted, which does not match the description of encrypting all data.
• Double disk encryption suggests encrypting data twice or using two layers of encryption, not necessarily covering the entire disk.
• Triple disk encryption similarly focuses on repetition rather than full coverage and is not a standard term.
• Segmented disk encryption would imply encrypting only certain segments, partitions or regions, which again conflicts with the idea of encrypting everything on the disk.

Common Pitfalls:
Some learners may be familiar with the phrase full disk encryption and may be momentarily unsure when they see Whole disk encryption instead. It is important to understand that the question is testing the concept rather than insisting on a single fixed phrase. Another pitfall is being tempted by options that sound stronger, such as Double or Triple disk encryption, even though these are not standard terms and do not address the requirement of covering the whole disk. Focus on the core idea in the stem: all data on the disk is encrypted, which directly leads to the concept of whole or full disk encryption.

Final Answer:
The correct answer is Whole disk encryption, which refers to technology where all data on a disk is automatically encrypted before being stored.