Optical storage basics – mapping bits on a CD-ROM surface On a CD-ROM, the raised, reflective areas that represent a logical 1 in the data encoding scheme are called ________.

Introduction / Context:
This question evaluates your knowledge of optical storage terminology on compact discs (CD-ROM). Data is encoded as transitions between two surface features. Understanding which feature is raised and what it is called helps clarify how the optical pickup converts surface patterns into digital bits.

Given Data / Assumptions:

• The medium is a CD-ROM with molded micro-features.
• The laser senses differences in reflectivity as the disc spins.
• We are asked to name the raised areas that correspond to a binary 1 in common descriptions.

Concept / Approach:
On a CD-ROM, “pits” are the recessed areas and “lands” are the raised, flat regions between pits. In simplified explanations, a binary 1 is associated with a transition between pit and land, but in many introductory treatments, the raised areas are referred to as lands and are commonly linked to logical 1 for identification, while pits are the depressions. Among the options, only “lands” correctly names the raised areas.

Step-by-Step Solution:

Verification / Alternative check:
CD literature consistently uses “pit” for the depression and “land” for the flat raised area. Regardless of detailed channel coding, the physical term for raised areas is lands, which is the focus of this question.

Why Other Options Are Wrong:

• Mounds: Not an industry term for CD features.
• Holes: Misleading; CDs do not have through-holes to represent bits.
• Pits: These are the recessed areas, not raised regions.

Common Pitfalls:

• Confusing the logical representation rules with the physical naming of features.
• Assuming “pit” means any visible feature rather than specifically the depression.

Final Answer:
lands