If # (w,x,y,z) means you multiply the sum of w and x by the sum of y and z, and # (2,3,4,z)=40,then z =

a. 5/3
b. 2
c. 4
d. 5
e. 8

w = 2

x = 3
y = 4
z = z

(2 + 3)(4+z) = 40
5(4+z) = 40
20 + 5 z = 40
5 z = 20
z = 4