• Option ‘A’, ointment, refers to something that's applied to the body for medical purposes.
• Option ‘B’, detergent, refers to a formulation.
• Option ‘C’, end, refers to the purpose where something ceases to exist.
• Option ‘D’, comfort, refers to a sense of relief or encouragement.
• From the above options, we are able to see that options ‘A’, ‘B’ and ‘D’ are incorrect as they do not have meanings that relate to the given the word.
  So, the right answer is option ‘C’, end, because it is that the exact antonym of the given word ‘origin’.

Hence, option C is the correct answer.