Only 4 are wrong here And you said 15/20

Let's re-evaluate:

1. C - ✅ Correct
2. A - ❌ Incorrect (Correct is B)
3. B - ✅ Correct
4. A - ❌ Incorrect (Correct is B)
5. D - ✅ Correct
6. B - ✅ Correct
7. C - ✅ Correct
8. A - ✅ Correct
9. C - ✅ Correct
10. B - ✅ Correct
11. A - ❌ Incorrect (Correct is B)
12. K - ❌ Incorrect (Correct is C, and 'K' was not an option)
13. A - ✅ Correct
14. B - ✅ Correct
15. B - ✅ Correct
16. C - ✅ Correct
17. C - ✅ Correct
18. B - ✅ Correct
19. D - ✅ Correct
20. C - ✅ Correct

There are 4 incorrect answers (questions 2, 4, 11, 12).
This means you have 16 correct answers out of 20.