Directions: Improve the bracketed part of the sentence.
Job performance is affected by a (vast) of factors.

Options

A. A) number
B. B) numerous
C. C) large
D. D) No Improvement

Answer

A

Explanation

a number of: a quantity of things.
Look at the sentence :
• A number of problems (some problems) have arisen. Here, number is the right usage.