From 1965 on, Yugoslavias standard of living has soared, but unemploym

From 1965 on, Yugoslavia’s standard of living has soared, but unemployment and prices too.
(A) but unemployment and prices too
(B) and also unemployment and prices
(C) but so have unemployment and prices
(D) and so also unemployment and prices
(E) but so did unemployment and prices

A new technique to crack this SC:

Grammar:
Two clause can be joined by the following ways:
1. Comma + FANBOYS (For, and, but, or, yet, so):
=> I am eating, and he is drinking.
2. Semicolon (;):
=>I am eating; he is drinking.
3. Semicolon (;)+ Conjunctive Adverb +Comma +Clause.
I am eating; then, he is drinking.

List of conjunctive adverbs:
accordingly, furthermore, moreover, similarly,
also, hence, namely, still,
anyway, however, nevertheless, then,
besides, incidentally, next, thereafter,
certainly, indeed, nonetheless, therefore,
consequently, instead, now, thus,
finally, likewise, otherwise, undoubtedly,
further, meanwhile.
4. Period + Capital:
=> I am eating. He is drinking.

Now, come to the sentence:
After comma, there is a FANBOYS. So, we need a clause, and a clause must have a subject and a verb. OPtions A, B, and D do not have verb. So, they are out. In the option E, the verb "did" is not parallel with the verb "has".
Answer is C.