Answer:
A. weak : frail
Explanation:
"weak" and "frail" are the best option among the words listed in the question.
"Thin" and "gaunt" refer to they physical appearance of a person, who looks "frail" or "weak". The words "weak" or "frail" having more of a figurative meaning, that is still similar to "thin" or "gaunt".
The insights that you can gain by studying psychology are the following:
Research - this helps the study become more productive in the needs of society, and at the same time discover various matters that involved it.
Perspective - with the study of behavioral science, you get to see a better perspective especially when encountering people.
Critical Thinking - it helps you gain more knowledge about your brain's activity, thus helping you develop more ideas in a better way.
Knowledge - in this world where people's minds have become the basis of society, you get to learn more about the world itself and how it develops.
