If markets are efficient, is there any benefit to active management? Explain

yesterday, the Dow Jones industrials gained 54 points. However, 1,704 issues declined in price while 1,367 advanced. Why might a technical analyst be concerned even though the market index rose on this day?

Consider a Treasury bill with a rate of return of 5% and the following risky securities:

Security A: E(r) = .15; standard deviation = ..2000

Security B: E(r) = .10; standard deviation = .1500

Security C: E(r) = .12; standard deviation = .3160

Security D: E(r) = .13; standard deviation = .2500

If you were going to form a complete portfolio consisting of the risk free asset and one risky asset from above, which risky asset would you choose.