The members of the opposition party made derogatory remarks about the policies of the government.

Answer: Option B

Derogatory : showing a critical or disrespectful attitude.
Praiseworthy : deserving approval and admiration.
Laudatory : (of speech or writing) expressing praise and commendation.
Respectable : regarded by society to be good, proper, or correct.
Admirable : arousing or deserving respect and approval.

Antonym of Derogatory is Laudatory