The correct answer is: A. risk averse.
The Markowitz model is a portfolio optimization model that assumes that investors are risk averse. This means that investors are willing to give up some potential return in order to reduce risk. The model helps investors to find the optimal portfolio that balances risk and return.
Option B, risk neutral, is incorrect because it assumes that investors are indifferent to risk. This is not a realistic assumption, as most investors are willing to pay a premium to reduce risk.
Option C, risk seekers, is incorrect because it assumes that investors are attracted to risk. This is also not a realistic assumption, as most investors are averse to risk.
Option D, risk moderators, is incorrect because it is not a specific term used in finance.