Good Afternoon! Can you please help explain this problem? Thank you!

Suppose 30 employees per day can produce 50 units of output. Assuming the law of diminishing marginal returns is present, to produce 100 units of output would require:

A) an additional 30 employees per day.

B) fewer than 30 additional employees per day.

C) more than 30 additional employees per day.

D) a total of 60 or fewer employees per day.