JAMB Commerce 2001 Question 39

Use the information below to answer questions 38 and 39.
Companies I, II, III and IV produce and sell electronic videos. Company I sells its videos for ₦14 000 each and offers advice on how to fix and operate them. Company II sells at ₦14 000 and its represenatives go to install at no additional cost. Company III sells at ₦15 500 and offers credit sales at ₦15 500 per video while company IV sells at ₦15 000 each.
Which of these companies offers after-sales services?

1. A.IV
2. B.III
3. C.II
4. D.I.