Consider the schema R = (S, T, U, V) and the dependencies S → T, T → U, U → V and V → S.

Let R = (R1 and R2) be a decomposition such that R1 ∩ R2 = ϕ.

The decomposition is

A. not in 2NF

B. in 2NF but not 3NF

C. in 3NF but not in 2 NF

D. in both 2NF and 3NF