A Metal Cylindrical Sleeve Has an Inner Radius a and an Outer

Multiple Choice

A metal cylindrical sleeve has an inner radius A and an outer radius B. The metal has a positive thermal expansion coefficient. When the sleeve's temperature increases

A) the outer radius decreases and the inner radius increases.
B) the inner radius decreases and the outer radius increases.
C) both the inner and outer radii decrease.
D) both the inner and outer radii increase.
E) The sleeve's length decreases.