Topic: Degree of Comparison,

Best Answer Explained in Below-:

The question "Which is - of the two?" implies a comparison between two items, and we need an adjective that indicates a relative comparison. In this context, the word "cheaper" is the comparative form of "cheap," which is used when comparing two entities.

Let's break down the options:

A) "cheep" refers to the sound made by a small bird or an unprofessional way of speaking and does not relate to value or cost.

B) "the cheap" suggests a noun phrase rather than making a direct comparison between two items, as it doesn’t indicate which is more affordable.

C) "the cheapest" is the superlative form, which is used to compare more than two items, not just two.

D) "the cheaper" is the only choice that correctly denotes that one of the two items being compared is less expensive than the other. It effectively answers the question by providing a comparative perspective, indicating that one option is more economical than the other.

Thus, "D: the cheaper" is the appropriate choice for the question posed.