Officials in Australia estimate that revenues from casinos

i doubt between (c) and (e).
(a) should sound: "an amount than that of..."
(b) should sound: "an amount higher than the previous year's one/amount"
(d) should sound same as (a)

so. since i have to choose one, i'd go with (e)

B.

I almost chose D for its conciseness but realized the referant which refers to what?

IMO , it should be C.

Article "the" is a determiner..which means that it should be followed by a noun. Plus ,a determiner should be followed by something very specific.

B, the closest one, may not be correct for the above reason.

REF : Webster

C is the correct answer. You have to avoid the Pronoun which in the last part of the sentence, because it seems to be referring to 1995. In the context of the sentence that makes no sense, since it should refer to the 80 billion dollars (remember, a which that follows a comma refers to the thing immediately before the comma). Using an amount is much clearer, and therefore we can eliminate D and E, since they use the inappropriate which.We can eliminate A because it is not idiomatic to say 30% more, but rather 30% higher. B can also be discarded because it uses the previous year's, without telling us exactly what belongs to the previous year.

Ofcourse Praetorian's explanation provides the adequate aegis.

Praetorian Rulzzzz.....


Vivek.