How Many of the Following Is/are Incorrect? I

Multiple Choice

How many of the following is/are incorrect? i.The importance of the equation E = mc² is that energy has mass.
Ii.Electromagnetic radiation can be thought of as a stream of particles called photons.
Iii.Electromagnetic radiation exhibits wave properties.
Iv.Energy can only occur in discrete units called quanta.

A) 0
B) 1
C) 2
D) 3
E) 4