Which of these collections of subsets are partitions on the set of bit strings of length 8?

a) The set of bit strings that end with 00; the set of bit strings that end with 01; the set of bit strings that end with 10; and the set of bit strings that end with 11.

b) The set of bit strings that end with 111; the set of bit strings that end with 011; and the set of bit strings that end with 00.

c) The set of bit strings that have 3k ones, where k is a non-negative integer; the set of bit strings that contain 3k+1 ones, where k is a non-negative integer; and the set of bit strings that contain 3k+2 ones, where k is a non-negative integer.