Answer: D) con-
Explanation: a prefix is a group of letters which we add to the beginning of a word to make a new word with a different meaning. A suffix is a morpheme added at the end of a word to form a derivative. In the word "convenient" the prefix is "con-" (corresponding to option D), this prefix means “with” or “thoroughly." The word "convenient" also has a suffix, which is "-ent." And the root word is "veni."
