A) 82
B) 84
C) 86
D) 88 ✓
He needs a total of 4 * 72 = 288 marks.
He had already achieved 60+50+90= 200 marks.
He needs a further 288 – 200 = 88 marks.
Basically, if s/he can’t work this out themself, they are unlikely to be capable of gaining enough marks.