Answer:
The correct answer here would be D) Diversification.
Explanation:
According to the efficient market hypothesis , it assumes that prices of stock reflects all the information ( of the past data ) and these information are available to general public , and here it is almost impossible to earn high returns from the stock ( but can only be achieved when low valued or under performing stocks are bought ) .
Passive investment approach is that type of approach where investor wants to earn higher return but with minimum number buying and selling trades. So in these given situations a portfolio manager should look to diversify the investors investment, so that by investing in various asset classes risk can be diversified and low costing could be maintained.