Question

renewable resources are considered as such because they can be replaced at a rate _______________. slower than they are used less efficiently than they are used faster than they are used

Explanation:

Renewable resources are those that can replenish themselves naturally. If they are replaced faster than they are used, they can sustain their availability. Options like "slower than they are used" would lead to depletion (non - renewable like some fossil fuels in a sense), and "less efficiently" is not the key criterion. The rate of replacement relative to use (faster) is what defines renewability.

Answer:

faster than they are used