The gerund phrase in the below sentence is used as a

Everyone enjoys watching a dolphin show.
a. subject
b. direct object ****
c. predicate nominative
d. predicate adjective

Right

Thank you

You're welcome.

To identify the gerund phrase in a sentence, it is important to understand what a gerund is. A gerund is a verb form that functions as a noun and ends in "-ing".

In the given sentence, the gerund phrase is "watching a dolphin show." It serves as a direct object because it answers the question "what does everyone enjoy?" The verb "enjoys" is followed by the gerund phrase which represents the action or activity that is enjoyed.

Therefore, the correct answer is b. direct object.