Read the following statements carefully :
Y : The resistivity of a semiconductor decreases with increase of temperature.
Z : In a conducing solid, the rate of collisions between free electrons and ions increase with increase of temperature.
Select the correct statement (s) from the followin :
A. Y is true, but Z is false
B. Y is false, but Z is true
C. Both Y and Z are true
D. Y is true, and Z is the correct reason for Y
