The correct answer is: C. Either I or II is implicit.
The statement “The end of a financial year is the ideal time to take a look at the performance of various companies” does not explicitly state that all companies take such a review at the end of a financial year, nor does it explicitly state that the performance data of various companies is available. However, both of these assumptions are necessary for the statement to be true.
If all companies did not take such a review at the end of a financial year, then the end of the financial year would not be the ideal time to take a look at their performance. Similarly, if the performance data of various companies was not available, then it would not be possible to take a look at their performance at the end of the financial year.
Therefore, either assumption I or assumption II must be implicit in the statement.