Answer: If his plan is going to work.
Explanation: Clearly Jack is using STEM for his plan so making sure that his plan works could possibly be the answer. I mean if you were creating a project you would want to make sure that it works and that you checked your STEM skills to go forward with the plan.
Analyzing the text, it helps the reader identify the authors choices.
The answer is A, Declan and Marissa got married years later, and their beautiful baby girl grew up to be a successful businessperson.