Stephen King's thrillers are always a gripping read. Here the word 'read' is a/an-- 

The correct answer is: c) noun

Explanation: In the sentence, "Stephen King's thrillers are always a gripping read," the word "read" is used as a noun. It refers to the act of reading or a piece of writing that can be read. In this context, "read" describes the quality of the experience of reading Stephen King's thrillers, making it a noun.

Now, let's explain why the other options are not correct:

a) verb: "Read" is not used as a verb in this sentence. It doesn't describe an action but rather the quality or experience of reading.

b) adjective: "Read" is not functioning as an adjective in this sentence because it doesn't modify a noun. Instead, it is a noun itself.

d) adverb: "Read" is not an adverb in this sentence either. Adverbs typically modify verbs, adjectives, or other adverbs, but here it is functioning as a noun.