The following question has three statements. Study the question and the statements and decide which of the statement (s) is/are necessary to answer the question.

What is the capacity of the cylindrical can?

I) The difference between the height and inner radius of the can is 7 cm.

II) Total sum of two circumferences of a circular base of the cylinder is 308 cm.

III) The cylindrical can has a thickness of 7cm.