The major product of the following reaction is :
`C_(6)H_(5)CH_(2)-underset(Br)underset(|)overset(CH_(3))overset(|)C-CH_(2)-CH_(3)underset(C_(2)H_(5)OH)overset(C_(2)H_(5)O"N"a)to`
A. `C_(6)H_(5)CH=underset(overset(|)(CH_(3)))(C)-CH_(2)-CH_(3)`
B. `C_(6)H_(5)CH_(2)-underset(overset(|)(CH_(3)))(C)=CHCH_(3)`
C. `C_(6)H_(5)CH_(2)-underset(overset(|)(OC_(2)H_(5)))overset(underset(|)(CH_(3)))(C)-CH_(2)CH_(3)`
D. `C_(6)H_(5)CH_(2)-underset(overset(|)(CH_(2)CH_(3)))(C)=CH_(2)`