The correct answer is: B. Only assumption II is implicit
The statement says that the regulatory authority has set up a review committee to find out the reasons for unstable stock prices. This does not necessarily mean that the investors will regain confidence in the stock market. The investors may or may not regain confidence, depending on the findings of the review committee.
However, the statement does imply that the review committee has the expertise to find out the causes for volatility in the stock market. This is because the regulatory authority would not have set up the review committee if it did not believe that the committee had the expertise to do the job.
Therefore, only assumption II is implicit in the statement.