Help me with this parallelogram please :)

Parallel sides of parallelogram are equal in length
[tex]\\ \sf\longmapsto AD=BC[/tex]
[tex]\\ \sf\longmapsto 6x+14=9x-4[/tex]
[tex]\\ \sf\longmapsto 9x-6x=14+4[/tex]
[tex]\\ \sf\longmapsto 3x=18[/tex]
[tex]\\ \sf\longmapsto x=6[/tex]
AD=6x+14=6(6)+14=36+14=50
Option D
The opposite sides of parallelogram are equal in length, so we can infer that :
now, let's solve for value of x :
we have to find the measure of AD,
Plugging the value of x as 6 :
The Correct option is D. 50