Consider a Treasury bill with a rate of return of 3% and the following risky securities:

1. Security A: E(r) = .11; variance = .0700
2. Security B: E(r) = .13; variance = .045
3. Security C: E(r) = .19; variance = .1000
4. Security D: E(r) = .10; variance = .03

The investor must develop a complete portfolio by combining the risk-free asset with one of the securities mentioned above. Which security the investor should choose as part of her complete portfolio to achieve the best CAL?