Which statement best describes the core security measures that Android uses to help keep applications and user data secure on a device?

Introduction / Context:
Mobile devices store personal information, emails, photos, and sometimes confidential business data. Android must therefore include robust security measures to protect both the system and user applications. Interview questions often ask about Android security to see whether candidates understand concepts such as sandboxing, permissions, and app signing. A clear explanation of these mechanisms shows awareness of how the platform reduces risk while still allowing third party apps to run.

Given Data / Assumptions:
Android is built on a Linux kernel that already includes a user and permission model.Applications are installed from stores or side loaded, and they need to be isolated from each other.Sensitive resources include contacts, location, camera, microphone, and network access.The question asks which statement best summarizes Android security measures.

Concept / Approach:
Android security uses several layered mechanisms. Each application runs in its own process with a unique Linux user ID, which creates a sandbox around its files and memory. Permissions control access to sensitive features such as camera, location, and contacts, and users must grant these permissions explicitly. Applications must be digitally signed, which ties updates to the same developer identity and allows the system to verify integrity. System updates and security patches also play a role, but the core of the model is sandboxing combined with permissions and app signing. A correct explanation must reference these elements explicitly and avoid claims that all apps run with full rights by default.

Step-by-Step Solution:
First, recall that Android assigns each application a unique Linux user ID and runs apps in separate processes, which creates isolation.Next, remember that when an app wants to use sensitive resources such as the camera or location, it must declare permissions and often request user approval.Then, consider that each app package is signed with a certificate, which the system uses to verify identity and prevent unauthorized updates.After that, recognize that features such as screen locks are important but are not the only security measure in the system.Finally, compare the options and select option A, which mentions application sandboxing, Linux permissions, app signing, and a permission based access model.

Verification / Alternative check:
Android platform security documentation lists key concepts such as the application sandbox, the permission system, secure inter process communication, and application signing. It emphasizes that each app has a distinct identity and that permissions are needed for sensitive operations. There is no statement that apps have full administrator rights by default or that network access is disabled on all devices. This official information confirms that option A accurately reflects the security measures Android uses.

Why Other Options Are Wrong:
Option B claims that Android gives every app full administrator rights and direct hardware access by default, which is the opposite of sandboxing and would be very unsafe. Option C suggests that Android disables all network connectivity to prevent attacks, which is unrealistic because many apps depend on network access. Option D says that users must compile the kernel themselves, which is not required for normal device use or app installation. Option E reduces security to screen lock patterns only, ignoring deeper system protections such as app isolation and permissions.

Common Pitfalls:
Some developers store sensitive data in plain text within app storage without considering that rooted devices or malware may access it. Others request more permissions than needed, which can discourage users and increase risk. A further pitfall is not keeping up with changes in the permission model, such as runtime permissions and background location restrictions. Understanding the layered security model of Android encourages better design choices, such as least privilege access and secure storage, and leads to safer applications.

Final Answer:
The correct answer is: Android uses application sandboxing, Linux user based permissions, app signing, and a permission based access model for sensitive resources.