Choose the correct answer for the given question from the options:
 
During an experiment:

a. Substance X expands the most on heating.
b. Substance Y expands slightly on heating.
c. Substance Z expands the least on heating.
 
i. Identify X, Y, and Z
Substance X, Y and Z are
 
ii. Arrange X, Y, Z in increasing order of compressibility.