The point of the sketch is (as I understand it) to ridicule our seriously-dumbed-down school exam system in which spelling your name right virtually guarantees you an A.
That's an excellent subject for a sketch but there's FAR too much dialogue and the point of the sketch is telegraphed to the audience long before they've been given a chance to get it for themselves.
Here's my version:
ADVISOR:
Welcome to the job centre. You've just taken your GCSEs?
DARREN:
Er . . .
ADVISOR:
Let me put it another way. Have just taken your GCSEs? A) Yes. B) No.
DARREN:
A) Yes.
ADVISOR:
What grade did you get for English? A) A, B) B, C) C, or D) D?
DARREN:
C) C. No, wait, it was D) D.
ADVISOR:
Are you sure? A) Yes or B) No.
DARREN:
A. It was D
ADVISOR:
And what about maths? D?
DARREN:
A
ADVISOR:
You got an A in maths?
DARREN:
No, I meant "A. Yes, I got a D"
ADVISOR:
Looking at the computer, I see Heathrow are looking for a baggage handler, there's a cleaning job in the children's department at Television Centre, and the Annual Bank Conference on Development Economics need a temporary receptionist. Which shall it be: A) BAA, B) CBBC or C) ABCDE?
DARREN:
Can I phone a friend?
END