The following statements (C1, C2, C3, C4) pertain to the characteristics of different type of canals. Which of the following statements is/are correct?

C1: A contour canal can irrigate command areas on both banks.

C2: It is possible to construct a contour canal with banks on one side only.

C3: In the case of a ridge canal, the number of cross drainage works is maximum.

C4: The side slope canal is aligned roughly at right angles to the ground contours.