What is a method to prepare Chromium(II) bromide?

A. Reaction of chromium with chlorine gas at 500-600 °C
B. Decomposition of chromium(III) bromide at 100-200 °C
C. Oxidation of chromium(III) bromide with oxygen gas at 200-300 °C
D. Reduction of chromium(III) bromide with hydrogen gas at 350-400 °C
Answer: 