The correct option is A quick
Tardy means delaying or delayed beyond the right or expected time. The opposite of tardy is quick, or prompt to understand, think, or learn; intelligent. Hence, Option A is correct. Among the rest of the options, enthusiastic means having or showing intense and eager enjoyment, interest, or approval, sluggish means slow-moving or inactive, progressive means favouring social reform.These do not express this antonym, hence incorrect.