I don't understand 'Component Options'

[xeophystaus]

Hello people.

I'm wondering, what do these 'Option', and 'Component Options' fields means in this PDF (last page)?

I understand that the numbers under 'Combination of components' means the paper number.
What I don't understand is the Option field. I recall that I took EX in my English Exam and meant 'Extended', but what about the rest?

Let's take Physics for example, under what circumstances I would take BX... EX... HZ....? Is there any 'default' one?

Kthx.

 

[Toomuch1995]

your school gets to choose them also depending on your time zone
have a look at this (attached)

 

[Toomuch1995]

although its for ICT but you can understand

 

[xeophystaus]

What if I was a private candidate and no one to choose for me? Am I supposed to go on EX one?