In the Mean-Standard Deviation Graph, Which One of the Following

In the mean-standard deviation graph, which one of the following statements is true regarding the indifference curve of a risk-averse investor?

A) It is the locus of portfolios that have the same expected rates of return and different standard deviations.
B) It is the locus of portfolios that have the same standard deviations and different rates of return.
C) It is the locus of portfolios that offer the same utility according to returns and standard deviations.
D) It connects portfolios that offer increasing utilities according to returns and standard deviations.
E) None of the options are correct.