Answer:
D
Step-by-step explanation:
The answer is D because the goal of engineering is to continuously improve the design of an item for the best possible outcomes. So A and C focus on the health side effect which can be important but aren't essential to an efficient design or are tested under the same umbrella and fixed. While B studying the form may allow for faster cooking but also for more side effects that can be addressed in a better design under D. That being said it's an opinion I hope helps or leads you to the right answer.