Idon´t understand how to do this at all

It was really confusing for me but I got it eventually
wx = 10 
vw = 22
wy = 20
vx = 32
wz = 30
vy = 42 
Here's how I solved it:
vz = 52 and xz = 20 right? Well, xz is two sections. 20 / 2 = 10, that's the value of wx,xy,yz because they're equal. wz = 30 ( 10 + 10 + 10 ). To get vw I took 52 (vz) and took away 30 (wz) and ended up with 22 (vw). For wy I simply added the two sections together to get 20. Essentially i did the same thing with vx and vy, I took vw (22) and added wx (10) to get vx (32) and then just added on xy (10) to get vy (42). :)

I know it's confusing but I did my best to explain it so you could understand it. 

It’s either a or c as the answer.