Boolean Sum is represented by "OR". I think u know how OR works, when both inputs are 0 ,0 then only output is 0, otherwise output is 1.
so check out each option. I think option C will be correct
X+Y+Z=1--------------------------------------------------(1)
XY=0--------------------------------------------------------(2)
XZ+W=1---------------------------------------------------(3)
option C says X: 1 Y: 0 Z: 1 W: 1
put these values in eq 1,2 and 3, it will satisfy..