Which of the Following Describes the Relation Between Price Elasticity $M R = P \left( 1 + \varepsilon _ { Q , P } \right)$

Which of the following describes the relation between price elasticity of demand and a monopolist's marginal revenue?

A) $M R = P \left( 1 + \varepsilon _ { Q , P } \right)$ .
B) $M R = P \left( 1 + \frac { P } { Q } \frac { \Delta Q } { \Delta P } \right)$
C) MR = 1+?_Q,P
D) $M R = P \left( 1 + 1 / \varepsilon _ { Qf } \right)$