Identify the part of speech of the highlighted word.
Being a devotee, he observes fasts on all pious days.

Correct option is B

The highlighted word “fasts” is a Noun.
Detailed explanation:
The word “fasts” refers to religious acts of abstaining from food, which are things/events. Here, it is the object of the verb “observes”, clearly functioning as a noun. It answers the question “observes what?” → fasts.
(उपवास / व्रत)
Grammatical rule used:
· A noun names a person, place, thing, or idea.
· When a word is used as the object of a verb, it is treated as a noun.
Example:
She keeps fasts during religious festivals.
Information booster:
The word “fast” can function as different parts of speech:
· Noun: a religious fast (उपवास)
· Verb: to fast for a day (उपवास रखना)
· Adjective: a fast runner (तेज़)
· Adverb: hold fast (मज़बूती से)
Here, “fasts” is clearly used as a noun.