The correct answer to this question is Gerund. To answer this question, we should first identify the verb in this sentence. The verb in this sentence is watching. Being that the verb ends in "ing," it can be defined as a gerund. This is because a gerund is a verb that ends in "ing." Other examples of gerunds include running, singing, playing, speaking, and writing.
In a sentence, a gerund functions as either an object or noun in the sentence. Gerunds can also be complements to the noun in the sentence. An example would be "The team's goal is helping the customers." The word Helping complements the goal of the team.