Hiking is a pleasant activity. how does the underlined gerund function in the sentence?
a. as a direct object
b. as an indirect object
c. as an appositive
d. as a subject

The answer is letter D. as a subject.

Explanation:

Gerunds are words formed by adding -ing to verbs. Even though they look like verbs, they behave like nouns, having the same functions nouns have in a sentence. A gerund can, for example, function as the subject of a sentence.

The subject of a sentence is what the sentence is about, the topic of the sentence.

Taking the information above into consideration, and also the fact that the only gerund in the sentence "Hiking is a pleasant activity" is the word "hiking", we can safely say that the gerund functions as a subject.

Hiking is what the sentence is about. Everything that comes after it has the purpose of giving us information about hiking. We get to know that hiking is an activity. We get to know not only that it is activity, but also that it is a pleasant one. We could dissect the sentence in the following way:

- Hiking --> subject

- is --> third-person singular liking verb

- a pleasant activity --> subject complement

“asleep in his bed” is personified.