Choice "C" is correct. Anticipating everything that could go wrong throughout the project plans is a part of risk assessment, not risk control.
Choice "d" is incorrect. Planning for risk includes risk assessment as well as risk control.
Choice "a" is incorrect. Risk and reward tradeoffs are inherent in project management.
Choice "b" is incorrect. Risk, the chance that something might go wrong, is inherent in every aspect of project management.