Answer: C) Calculations are often unnecessary because we can usually rely on common wisdom.
Explanation: According to the ethical theory of John Stuart Mill about utilitarianism is that morality of actions are used for defining the result or outcome about the happiness . Calculations are thus not a requirement for the utilitarianism.
Other options are incorrect because training is not required for simplification of calculation. Â It is not an issue for every theory and neither is the reason for low knowledge about morals.Thus, the correct option is option(C)