The correct option is A (x+y+z)
Given: ax+by+bx+az+ay+bz(a+b)
Consider the numerator,
ax+by+bx+az+ay+bz=(ax+ay+az)+(bx+by+bz)
Taking 'a' common from the first group and 'b' common from the second group, we get
=a(x+y+z)+b(x+y+z)
=(x+y+z)(a+b)
Therefore,
ax+by+bx+az+ay+bz(a+b)=(x+y+z)(a+b)(a+b)=(x+y+z)