The main goal of sustainable development is to:

a. use natural resources such that they do not decline over time.

b. re-evaluate and re-implement management plans over time.

c. involve more countries in conservation efforts.

d. use only natural resources in the construction of new buildings.

The correct answer is letter "A": use natural resources such that they do not decline over time.

Explanation:

Sustainable development refers to the efforts companies make to handle their business both reaching its economic goals to make sure the firm will remain operational through the years but considering the preservation and conservation of the natural resources used in its manufacturing process over the years.

Sustainable development aims to provide future generations with available resources so they can also perform their activities without shortages constraints.