Treatment of the following stereoisomer of 1-bromo-1,2-diphenylpropane with sodium ethoxide in ethanol gives a single stereoisomer of 1,2-diphenylpropene.

Draw the E2 elimination product of the reaction. Take into account that the starting stereochemistry affects the resulting double bond stereochemistry.

C6H5 H H3C C6H5 Br CH3CH3O* Na+ CH3CHOH