Correct Answer - Option 1 : T and S
S is lighter than the only Q so we can say that Q is the heaviest and S is 2nd heaviest. P is heavier than 3 person which means he is 3rd heaviest person.
R is not the lightest, and R can also not be 4th heavier because T is heavier than R, so R is the 2nd lightest. As we know T is heavier than R, therefore T is 4th heaviest. Now the remaining U has to be lightest of all.
Now the required arrangement is: Q > S > P > T > R > U