Which BEST identifies and explains the function of the word gardening as it is used in this sentence?

Gardening is a pleasant and productive pastime for people of all ages.

A. In the selected sentence, the word gardening is a gerund, and the gerund phrase functions as the subject.

Explanation:

A gerund is seen in a sentence when a verb which stops with"ing" acts as a noun. It can also act as a subject, predicate noun, objects of the preposition, and direct objects in a phrase. Examples are, I love playing on the tiles, when are you going to visit her? I love eating fried plantain, dancing is my hobby, etc.

Given the above, the word "Gardening" is a gerund that acts as a subject in the sentence.