1. compact disc singular => box, not boxes => d & e are out

2. c package becomes action by preceding "to", but has no subject= > it is out


3. in b "where" usually corresponds to a direction not a thing , so i would go with a

1. compact disc singular => box, not boxes => d & e are out

It is compact disc manufacturers and not compact disc.
You have to look for PRODUCT which is singular and hence need BOX

I don't think it is the case of compact disc or compact discs.

we never say "apples grower" else say "apple grower".

I inferred it like this:-

b)"where" is used to refer to a place. So, here it is referring to a box. So, wrong.
c)"in which to" - awkward construction
d)Since, they are talking about "their product" not "theirs products". So, a product cannot be packed in a number of boxes rather in a box.
e)Same as D.

Please correct me if i am wrong.

Agree with James 83