The Required Rate of Return on a Certain Bond Changes

The required rate of return on a certain bond changes from 12 percent to 8 percent, causing the price of the bond to change from $900 to $1,100. The bond price elasticity of this bond is

A) -0.36.
B) -0.44.
C) -0.55.
D) -0.67.
E) 0.67.