When more resources are added, the additional output that these resources produce decreases. This is called the:

law of diminishing returns.

Explanation:

The law of diminishing returns refers to decrease or fall in the marginal productivity i.e. if one input of the production rises, while all other inputs would remain fixed

Since in the question it is mentioned that when at the time resources are added an extra output that produced would be decreased so this is we called as law of diminishing returns and hence the same is to be considered

answer; exemplars;