I was told that if a student gets a C in a class which they need a B or higher in for their major, and they go on to take the next course in the sequence, they cannot take the prior course again for a new grade.

If a student gets a C in CMSC 202, can they take both CMSC 202, CMSC 331 and CMSC 341 the next semester or is that a violation of these retarded rules?  (the courses themselves only require a C in 202 in order to take)

Thanks for your help, and please say how you know what you know.