A researcher studying organic compounds has found that five different molecules - T, W, X, Y and Z-form chains According to the following rules :
i) A chain consists of three or more molecules, though the molecules in the chain are not necessarily different.
ii) T is never found on either end of a chain.
iii) If W appears in a chain, it appears more than once.
iv) X is never found next to Y in a chain.
v) W is never found on the end of a chain unless Z is found somewhere in the chain.
vi) If Y appears in a chain, Z appears also.
The chain-W W T Y Z X can be changed into another chain by carrying out any one of the following EXCEPT

Options

A. Replacing the Y molecule with a W molecule
B. Replacing the Y molecule with an X molecule
C. Replacing the X molecule with a T molecule
D. Interchanging the T and the Z molecules

Answer

C

Explanation

Again, test each of the resulting chain.
1) W W W Y Z X T This sequence is a possible chain.
2) W W T X Z X This sequence is a possible chain.
3) W W T Y Z T This is not a chain, because T is on one end.
4) W W Z Y T X This sequence is a possible chain.
5) W W T X Z Y This sequence is a possible chain.