What portion of the proposal indicates whether the research will be exploratory, descriptive, or causal?

The correct answer to the following question will be "The research method".

Explanation:

Research methods seem to be the approaches, procedures, or methods used to gather evidence or data for study to find hidden knowledge or produce a better comprehension of a subject. The study aim is indeed an iterative process of fixing and testing theories that will contribute to the recognition of some of these objective truths.

Therefore, it's the right answer.