If 'tee see pee' means 'Drink fruit juice', 'see kee lee' means 'Juice is sweet' and 'lee ree mee' means 'He is intelligent', which word in that language means 'sweet' ?

Answer: B. kee

In the first and second statements, the common word is 'Juice' and the common code word is 'see'.
So 'see' means 'Juice'.
In the second and third statements, the common word is 'is' and the common code is 'lee'.
So, 'lee' means 'is'.
Thus, in the second statement, the remaininig word 'sweet' is coded as 'kee'.
Hence the answer is (b).