The answer should be C.
(1) if y is negative, then either X or Z must be negative. So if y is negative and Z is negative, then the overall product will be positive. However, if Y is negative and X is negative, then the overall product will be negative because y^5 will be negative and any positive number multiplied by a negative will always be negative.
(2) No information about X. for all we know, X could be a zero.
(1&2) So we know that X is not a zero. But when you consider the different scenarios, the product will always be negative since X^2 will always be positive. So when either X or Z has to be a negative, the overall product will always be negative. We know this because their powers are odd and so it will maintain their original signs.