Correct option is B
Given: 'STEP' is related to 'WXIT' and 'FILL' is related to 'JMPP' with same logic.

Logic: Letters are increasing + 4 place.
For, STEP - WXIT
S + 4 = W, T + 4 = X, E + 4 = I, P + 4 = T
For, FILL - JMPP
F + 4 = J, I + 9 = M, L + 4 = P, L + 4 = P
Similarly,
THAT - ?
T + 4 = X, H + 4 = L, A + 4 = E, T + 4 = X
So, THAT is related to XLEX.
Thu, correct option is (b).