The Graph Shows the Voltage Across and the Current Through $\varOmega$

Multiple Choice

The graph shows the voltage across and the current through a single circuit element connected to an ac generator.
-What is the reactance of this element?

A) 20 $\varOmega$
B) 25 $\varOmega$
C) 30 $\varOmega$
D) 35 $\varOmega$
E) 40 $\varOmega$