What Is the Major Organic Product Obtained from the Following $\mathrm{CH}_{3} \mathrm{CHBrCHBrCH}_{3}$

What is the major organic product obtained from the following reaction? $\mathrm{CH}_{3} \mathrm{CHBrCHBrCH}_{3}$$\underset{\mathrm{DMSO}}{\stackrel{\mathrm{NaNH}_{2}}{\longrightarrow}}$

A) (E) 2-butene
B) (Z) 2-butene
C) 2-butyne
D) 1-butyne