Answer:
b.
Step-by-step explanation:
In this scenario, the best theme for the analyst to look into would be a comparison of the commercial prospects of new aircraft models. Meaning a deep look into how well the new aircraft models will do in the commercial markets. This is because the stock prices of United Technologies and Rolls Royce ultimately depends on how well the company's products do when they get released. Therefore in order to decide which investment will return the highest ROI, it is best to compare their commercial prospects.