21. You have determined the following data on three stocks.

Stock	Standard Deviation ()	Beta ()
X	0.15	0.79
Y	0.25	0.61
Z	0.20	1.29

To minimize risk, you will choose Stock ___ if held individually and Stock ___ if held as part of a well-diversified portfolio.

____

A) X; X

B) X; Y

C) Y; Z

D) Z; X