Which statement below isincorrect?

a.

Theoretically, in the survey study, we can eliminate the systematic error to zero.

b.

If the volatility of the underlying asset increases, the call option value will increase but the put option value will decrease.

c.

Compared to active mutual funds, passive mutual funds charge a lower management fees on average.

d.

Compared to simple random sampling, it is easier for researchers to manipulate the results in the systematic random sampling.