Consider the Following 0 - 1 Integer Programming Problem

Consider the following 0 - 1 integer programming problem: If we wish to add the constraint that X must be positive, and that only Y or Z but not both can be positive, how would the additional constraint(s) be written?

A) X + Y + Z ≤ 3, Y + Z ≤ 1
B) X ≤ 1, Y + Z = 1
C) X ≤ 2, and Y ≤ 2, and Z ≤ 2
D) X = 1, Y + Z ≤ 1
E) None of the above