A Machinist Needs to Remove a Tight Fitting Pin of Material

Multiple Choice

A machinist needs to remove a tight fitting pin of material A from a hole in a block made of material B. The machinist heats both the pin and and the block to the same high temperature and removes the pin easily. What statement relates the coefficient of thermal expansion of material A to that of material B?

A) Material B has a greater coefficient of expansion than does material A.
B) The situation is not possible, heating block B will shrink the hole in the material as the material expands with increasing temperature.
C) Material B has the same coefficient of expansion as does material A.
D) Material B has a negative coefficient of expansion and A has a positive coefficient of expansion.
E) Material A has a greater coefficient of expansion than does material B.