Final answer:
The correct answer is 'would', as it indicates Priscila's preference about not investing in the stock market.
Step-by-step explanation:
The correct answer to the question is d) would. The sentence should read, "Priscila would rather not invest her savings in the stock market." This uses the modal verb 'would' to indicate a preference in a polite or hypothetical context, which is what the sentence is conveying about Priscila's investment choice.
Modal verbs are auxiliary verbs used to express ability, possibility, necessity, permission, or likelihood in a sentence. Examples include "can," "could," "may," "might," "shall," "should," "will," "would," "must," and "ought to." They add nuance to the meaning of the main verb in a sentence.