Synonyms are words which have the same or nearly the same meaning in the same language.
Antonyms are words which have opposite meaning in comparison to the other.
Option C)End is correct as the word origin means the point or place where something begins, arises, or is derived and the word end means a final part of something, especially a period of time, an activity, or a story. Both the words are opposite of each other.
The other options are not correct as ointment,detergent, and comfort are not the opposites of the word origin.