73.

Answer and Explanation

Your Answer is

Correct Answer is C

Explanation

Item A: There is no single comma between the subject (approach) and the predicate (remains), which is the subject of this sentence, and A is wrong.

Item B: diagrammatic adjective, modified noun approach, unsigned in the middle, B error.

Item D: Approach to mapping as a whole, no symbols appear in the middle, and D is wrong.