There are three objects X, Y, and Z, that have triangular, square and pentagonal shapes, have red, green and blue colours and are made up of different materials gold, silver and bronze such that, X is red but not square. Y is made up of silver but it is not green. X is made up of bronze and Z has a pentagonal shape. What is Z made up of?​​

Given: 

There are three objects X, Y, and Z, that have triangular, square and pentagonal shapes, have red, green and blue colours and are made up of different materials gold, silver and bronze such that, X is red but not square.

Y is made up of silver but it is not green.

X is made up of bronze and Z has a pentagonal shape.

Z is made up of Gold.

Thus, correct option is (b).