Suppose you have all of your assets tied up in a single investment with an expected return of 8% and a standard deviation of 10%. Your investment advisors suggest adding a new investment with an expected return of 7% and a standard deviation of 12%. This seems like:

A. Cannot be determined from the information given.

B. a bad idea because it will lower your return.

C. a bad idea because it will increase your risk.

D. a good idea because more investments are always better.