15. i. The warp [A] / woof [B] of India's economic structure is still…

Correct answer: AAAA (Option 1) — the right word in every sentence is choice [A].

i. warp [A] — The idiom is “warp and woof” (also “warp and weft”), a weaving metaphor for the very foundation or essential structure of something. In “The ___ of India’s economic structure is still agriculture,” the lead word of the idiom, “warp,” fits as the foundational thread. Hence [A].

ii. of [A] — “The opposite of” is the standard collocation when contrasting two ideas or actions (“do the opposite of what I advise”). “Opposite to” is used for physical position, not for contrast, so [A] is correct.

iii. prurient [A] — “Prurient” means having or appealing to an excessive interest in sexual matters. Disks secretly circulated would carry lewd, i.e. prurient, content. “Prudish” (excessively prim about sex) is its opposite and makes no sense here. Hence [A].

iv. atheist [A] — Someone who holds that God’s existence cannot be proved or known is an agnostic (agnosticism = a claim about knowledge). So he WAS an agnostic and was therefore NOT an atheist (atheism = the belief that no God exists). The blank “he was not an ___” is completed by “atheist.” Hence [A].

Combining the four choices i–iv gives A, A, A, A = AAAA, which is Option 1.