Investment Banker: Democracies require free-market capitalist

E) The nations whose anticapitalistic measures the people in question bemoan HAD totalitarian regimes in the past

CONCLUSSON: "People who bemoan the seemingly anticapitalistic measures certain governments are currently taking are being hasty." WHY?
PREMISE: Repressive measures against capitalistic developments are required DURING the transition from a totalitarian regime to a democracy.

Here we see a logical gap. "Certain governments" in the conclusion must be DURING the transition from totalitarian regimes to democracies.
I think in Assumption questions, we should ALWAYS use the negation technique when we have come to a few remaining answer choices. If you negate (E), it becomes as follows: "The nations whose anti capitalistic measures the people in question bemoan DID NOT HAVE totalitarian regimes in the past." If so, these nations can not be currently in the TRANSITION from totalitarian regimes to democracies." Then repressive anticapitalistic measures DO NOT apply to those countries. This breaks down the Conclusion. Hence, (E) is incorrect.

Investment Banker: Democracies require free-market capitalist economies, because a more controlled economy is incompatible with complete democracy. But history shows that repressive measures against capitalistic developments are required during the transition from a totalitarian regime to a democracy. Thus, people who bemoan the seemingly anticapitalistic measures certain governments are currently taking are being hasty.

Which one of the following is an assumption required by the investment banker's argument?

A) No current government has reached as complete a state of democracy as it is possible for a government to reach - WRONG. An extreme situation that is not necessarily true.

B) The more democratic a country is, the less regulated its economy must be - WRONG. No relation as such is found nor required for the passage.

C) The need for economic stability makes the existence of partially democratic governments more probable than the existence of fully democratic governments - WRONG. Nothing wrong as such but the red text is questionable.

D) A free-market economy is incompatible with a nondemocratic regime - WRONG. A big claim not necessarily true.

E) The nations whose anticapitalistic measures the people in question bemoan had totalitarian regimes in the past - CORRECT. If not then bemoaning makes sense.

For me only C and E were of any significance. Unfortunately, chose C. Thus, choosing is bad.
The bigger factor to consider is that it is talking about transition in which nothing is absolute. And this is where C falls apart, only slightly though.