Step-by-step Solution:

Each letter in the word 'BEAN' is shifted forward by one position in the alphabet: B -> C, E -> F, A -> B, N -> O. Applying the same logic to 'CORN': C -> D, O -> P, R -> S, N -> O. The coded word is 'DPSO'. The provided correct option is 'DPOS', which seems to be a typo in the source document as the R and S are swapped.