Opposite sides of a parallelogram are congruent, so make BC and AD equal to each other in an equation.
BC = AD
16 + 2x = 10 + 8x
Subract 2x from both sides.
16 = 10 + 6x
Subtract 10 from both sides.
6 = 6x
Divide both sides by 6.
x = 1
B) 1 is your answer.