Prestige, borrowed from French, is derived from Latin praestigium, meaning illusion, or juggler's trick.

Is it

A) amelioration

B) pejoration

The correct answer is A, amelioration. In linguistics pejoration is a term used to signify how a word's meaning becomes downgraded and goes from having a positive meaning to having a negative meaning. Amelioration is a reverse term, it is a phenomenon where one word over time acquires a more positive meaning, as is the case with prestige, which now has a positive connotation.