Select the option that is related to the third letter-cluster in the same way as the second letter-cluster is related to the first letter-cluster. CA : GH :: TK : ?

XR YR YS YS

XR

CA : GH :: TK : ? The logic followed here is : AS C → (+4) → G A → (+7) → H Similarly T → (+4)  → X K → (+7) → R