Variable returns from an investee include:

a$.$

dividends from ordinary shares that will change based on the profit performance of the investee

b$.$

fixed interest payments from a bond, as they expose the investor to the credit risk of the issuer of the bond, namely the investee

c$.$

fixed performance fees for management of the investee$$s assets, as they expose the investor to the performance risk of the investee.

d$.$

all of the options are correct.