In the Factorial Experiment, Where a Is the Number

Multiple Choice

In the factorial experiment, where a is the number of levels for factor A, b is the number of levels for factor B, and r in the number of replications of each of the ab factor combinations, the degrees of freedom for interaction is given by:

A) (a1) (b1)
B) (a1) (r1)
C) (b1) (r1)
D) ab(r1)
E) (b + 1) (r + 1)