Rainy Day Investment Services wants to provide its investors with meaningful statistics to evaluate a stock investment opportunity for them to interpret their risk. Rainy Day has some investors with undiversified portfolios and some with diversified portfolios. Rainy Day should use:

Group of answer choices

Standard deviation for both types of investors.

Standard deviation for investors with an undiversified portfolio and covariance for investors with diversified portfolios.

Covariance for both types of investors.

Covariance for investors with an undiversified portfolio and standard deviation for investors with diversified portfolios.