K, L, M, W, X, Y and Z scored different marks in an exam. K scored more than both L and W but less than Y. X scored less than only Y. Neither L nor M scored the lowest marks. Z scored more than L but less than M. K scored more than M. Who scored the third-lowest marks?

​​K scored more than both L and W but less than Y:

K > L, K > W, Y > K

X scored less than only Y:

X is the second-highest scorer. Therefore, X < Y 

Neither L nor M scored the lowest marks:

L and M did not score the lowest marks.

Z scored more than L but less than M:

M > Z > L

K scored more than M:

K > M

Arranging the scores in order:

From the given clues:

K > L, K > W, K > M, and K < Y.

X < Y, and X > all except Y.

M > Z > L.

Now, let's arrange all the people in order of their scores based on these relationships:

Y > X > K > M > Z > L > W

The third-lowest scorer is Z.

Thus, correct option is (b).