问题：
Athe decision as to the allocation between a risk-free asset and a risky asset.
Bthe decision as to the allocation among different risky assets.
Cconsiderable security analysis.
Dthe decision as to the allocation between a risk-free asset and a risky asset and the decision as to the allocation among different risky assets.
Ethe decision as to the allocation between a risk-free asset and a risky asset and considerable security analysis.
