Antonym of RADICAL

Answer: Option D

Radical : (especially of change or action) relating to or affecting the fundamental nature of something; far-reaching or thorough.
Uncompromising : showing an unwillingness to make concessions to others, especially by changing one's ways or opinions.
Basic : forming an essential foundation or starting point; fundamental.
Thorough : complete with regard to every detail; not superficial or partial.
Superficial : not thorough, deep, or complete; cursory.

Antonym of Radical is Superficial