When borrowing and lending at a risk-free rate are allowed, which Capital Allocation Line (CAL) should the investor choose to combine with the efficient frontier?

 I) The one with the highest reward-to-variability ratio.

 II) The one that will maximize his utility.

 III) The one with the steepest slope.

 IV) The one with the lowest slope. 

Group of answer choices

 A: I and III 

B: I and IV

C: II and IV 

D: I only 

E: I, II, and III