Which sentence contains a gerund?

A gerund is a verb form that ends in -ing and functions as a noun in a sentence. It is essential to recognize gerunds because they can be used as the subject, object, or complement in a sentence.

In the correct choice, the presence of a word ending in -ing serving as a noun indicates that this sentence includes a gerund. For instance, if the sentence emphasizes an action or a concept derived from a verb and uses the gerund form appropriately within the grammatical structure, it meets the definition of containing a gerund.

The other sentences may include present participles or different forms of verbs that do not fulfill the noun role. Without identifying a clear action acting as a noun, they do not exemplify the characteristic structure of a gerund. This highlights the unique nature of the selected sentence as it explicitly shows the use of a gerund, demonstrating its function effectively within the sentence.