Final answer:
The synonym for "conceal" that becomes a past tense verb meaning "went quickly" when two letters are switched is "hide" because "hied" (past tense of hie) means to go quickly. Option a is correct.
Step-by-step explanation:
The student's question is about finding a synonym for the word "conceal" that, when two letters are switched, becomes a past tense verb meaning "went quickly".
After reviewing the options provided: a) Hide, b) Flee, c) Speed, d) Creep, the correct answer is a) Hide. When you switch the 'i' and 'd' in "hide", it becomes "hied", which is a past tense form of the verb 'hie' meaning to go quickly or hasten.