The option that best describes what Hanaa is doing to solve the problem is "d. Costs and benefits".Hanaa is the head of the engineering department in Beit Company and she is informed of a chemical leakage in the pond nearby. She begins to study the situation and the options available to her. One of the things that she takes into consideration is the costs and benefits of each option. She carefully considers the expenses and the available funds to fix the problem. She also takes into account people's health, which is a benefit of fixing the problem, and the potential cost of not fixing the problem, which could lead to negative health effects and legal liabilities. Therefore, option d. Costs and benefits, best describes what Hanaa is doing to solve the problem.