Which word in the sentence is the direct object?

The delighted children picked pumpkins from the patch.

a. delighted

b. children

c. patch

d. pumpkins

A direct object is the part of the sentence that is somehow manipulated by the subject, and the type of the manipulation is described by the verb.

here the subject is "The delighted children" and the verb is "picked"

the direct object is "pumkins" - the correct answer is d.