By studying the suffix, the reader can determine that “impetuous” most likely means

“having the quality of acting impulsive or with emotion.”
“someone who is filled with impulsiveness and emotion.”
“someone who acts without impulsiveness or emotion.”
“having a state or condition that is impulsive or emotional.”

The correct answer is A. "Having the quality of acting impulsive or with emotion"

Explanation:

A suffix is a morpheme or part of a word that is added to the stem of a word (the main part of the word or a word itself) to create a new meaning. In the case of "impetuous", the steam of this word is "impetus" which means a force that leads to action or impulse and the suffix is "ous" which is mainly used to form adjectives and thus indicates having the quality of the word it is attached to. As it happens in "Humor" (funny or comic)  and "Humorous" (having humor or being comical). Thus, impetuous means having the impetus, it means the quality of acting impulsively. Thus, if someone studies suffixes, he/she will determine "impetuous" means having the quality of acting impulsive or with emotion.

the answer is