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.
Which of the following could be converted into a chain by adding Z and rearranging the molecules ?

Options

A. W W _ Y T X
B. W X T Y _ Y
C. X _X Y T Y
D. _ X X T W Y

Answer

A

Explanation

Again, analyst the defect in each sequence.
1) Here, we have a W on the end of the sequence without a Z, and we have a Y without a Z. Placing a Z in the space where there is a desh solves both problems, and the resulting sequence - W W Z Y T X - is a chain.
2) Here, a W appears without another W, W appears on the end wihout Z and Y apppears without Z. So we need both W and Z to turn this sequence into a chain, but we have only one missing link.
3) Regardless of what is substituted for the dash in this sequence, the resulting sequence will have an X next to a Y, so it cannot be a chain .
4) Here, we need both a W (for the one W) and a Z (for the Y) to turn this into a chain, but we have only one dash, so this sequence cannot be salvaged.
5) Regardless of what is substituted for the dash, T will still be on the end of the sequence, so this sequence cannot be a chain.