Which of the Following Statements Regarding Arc Elasticities Is TRUE

Which of the following statements regarding arc elasticities is TRUE?

A) the arc elasticity value is exactly equal to point elasticity.
B) arc elasticities do not measure responsiveness; only point elasticities do this.
C) arc elasticities use derivatives in their calculations.
D) arc elasticities are elasticities calculated between two points or two values of a variable.
E) the arc elasticity measures the responsiveness of Q_x to extremely small changes in the value of an independent variable.