When saving and restoring registers with PUSH and POP, which of the following is correct?

a$.$

Both PUSH and its corresponding POP occur within the same loop.

b$.$

The operand order is the same between PUSH and POP, as in:

$$ push eax

$$ push ebx

$...($some other code$)$

$$ pop$$ eax

$$ pop$$ ebx

c$.$

PUSH is coded before a loop begins, but the corresponding POP is inside the loop.

d$.$

The operand order is reversed in POP, as in:

$$ push eax

$$ push ebx

$...($some other code$)$

$$ pop$$ ebx

$$ pop$$ eax