Step 1: Finding the relevant textual evidence The passage states: "An undeveloped sense of humour lacks a social skill that puts him or her at a disadvantage."
Step 2: Explanation This statement directly shows how lacking a sense of humour can make social interactions difficult, placing a person at a disadvantage in social settings.
A compound (A) with molecular formula $C_4H_9I$ which is a primary alkyl halide, reacts with alcoholic KOH to give compound (B). Compound (B) reacts with HI to give (C) which is an isomer of (A). When (A) reacts with Na metal in the presence of dry ether, it gives a compound (D), C8H18, which is different from the compound formed when n-butyl iodide reacts with sodium. Write the structures of A, (B), (C) and (D) when (A) reacts with alcoholic KOH.