B.55 degrees is the answer
The answer would be 55 because the total degree together is 180 degrees
so you add 40 degrees plus 30 degrees and get 70 degrees
then subtract 180-70=110
and because there is 2 y variables so you divide 110 divided by 2
so then you would get ur answer of 55 degrees
to check 40+55+30+55=180
Hope this helps :)