Answer: D) The underlined verb "was celebrated" is in passive form.
Step-by-step explanation: When the verb is active, the subject of the verb is doing the action (for example: Mary eats the cake), when the verb is passive, the subject undergoes the action rather than doing it (for example: the cake is eaten by Mary). In the given sentence, the underlined verb "was celebrated" is in passive form, because the subject in the sentence (National gumdrop day) is also the direct object, and the actual subject (the person or people that are performing the action of the verb) isn't even in the sentence.