These are confusing question. People tend to think A/B/C/D only if the answer is yes; i.e. only if the two statements prove that x(y+z) = 0. But you have to look at the trap here; even if you are able to deduce that x(y+z) != 0 , you know the answer.
Statement 1 can be interpreted as "y and z" have same sign...
Statement 2 can be interpreted as "x and y" have same sign...
Combining these two, we know that x, y, & z; all have the same sign, and from the stem you know that none of them is zero. So it can be deduced that the result will never be zero...
simplyjat