Select the most appropriate option to fill in the blank in the given sentence with a suitable conjunction.
I couldn't sleep ___ very tired.

Correct option is A

The correct option is (a) despite being.

Explanation:
The sentence expresses a contrast — the speaker could not sleep even though they were very tired. The blank must be filled with a word or phrase that introduces this contrast while being grammatically correct with the phrase that follows (very tired).

Correct answer – despite being:
Despite is a preposition and must be followed by a noun, pronoun, or gerund phrase (noun + ing), not a full clause. The structure despite being very tired is grammatically correct.
(Hindi meaning: बहुत थके होने के बावजूद)
Example: Despite being exhausted, she continued to work.

Grammatical Rule (English):

• Despite / In spite of + noun / pronoun / gerund (V₁ + ing)
• Although / Though / Even though + full clause (subject + verb)

• (b) in spite of I was – Grammatically incorrect; in spite of must be followed by a noun or gerund, not a clause (I was).
• (c) although I had – Requires a complete clause; although I had very tired is meaningless because very tired is an adjective phrase, not a verb phrase following had.
• (d) despite I was – Grammatically incorrect; despite cannot be followed by a subject + verb clause.