The word "respite" means a short period of rest or relief from something difficult or unpleasant. To find the most appropriate antonym, we need to look for a word that means the opposite of "respite," which would be a situation or action that is not relieving or restful.

Option 1: "Commencement" means the beginning of something. It doesn't convey the opposite meaning of "respite."

Option 2: "Solicit" means to ask for or request something. It is unrelated to the concept of "respite."

Option 3: "Adverse" means unfavorable or harmful. While it is not directly related to "respite," it doesn't provide the opposite meaning.

Option 4: "Frustrate" means to prevent the achievement of a goal or to cause feelings of disappointment or annoyance. This option is more closely related to the opposite concept of "respite" because it implies a lack of relief or rest from difficulties.

Therefore, Option 4, "Frustrate," is the most appropriate antonym for "respite."