The correct option is D regressive
The word 'progressive' refers to happening or developing gradually or in stages.
Option A, abhorrent refers to something inspiring disgust and loathing.
Option B, retrograde refers to reverting to an earlier and inferior condition.
Option C, obstructive refers to causing a blockage or obstruction.
Option D, regressive refers to returning to a former or backward state.
Thus, according to the meaning, the word 'regressive' is the opposite of the word 'regressive'.