_______ on this beach is much more pleasant than _______ in the office.

The correct answer is: a) Lying, sitting

In this sentence, the first blank should be filled with a verb, and the second blank should be filled with a gerund (a verb form that functions as a noun). Let's break down the explanation:

"Lying" is the ‘ing’ form of the verb "lie," which means to recline or be in a horizontal position. In this context, it's used as a verb.

"Sitting" is the gerund form of the verb "sit," and it functions as a noun in this sentence.

The sentence is comparing two actions: lying on the beach and sitting in the office. Therefore, option "a) Lying, sitting" is the correct choice as it uses the appropriate verb and gerund forms to complete the sentence correctly.