Difference between success and progress

Test No. [color=blue]incompl/advan-24 “Employment and Training”, question 7

The head of department acknowledged that the of the section was largely due to high quality support staff.

(a) success
(b) progress
© business
(d) future

Test No. [color=blue]incompl/advan-24 “Employment and Training”, answer 7

The head of department acknowledged that the success of the section was largely due to high quality support staff.

Correct answer: (a) success

Your answer was: [color=red]incorrect
The head of department acknowledged that the progress of the section was largely due to high quality support staff.
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help me grasp the concept here?

This word would be too vague here because it is not clear enough what sort of progress it would be and where it has gone. Success is more appropriate.