Which statement is true about a number and its additive inverse

a: the product is always one.
b: their sum is always one.
c: they are always reciprocals of each other
d: their sum is always zero.

The first one, i believe, would be correct. all the others have one thing in common, and that's that they have repeating numbers. in the second one, x and y have repeating 6's and 3's, and in the third, x and y have repeating 6's as well. in the last one, there are repeating 3's. the first one has no repeating numbers.

Ok jnibinubu y y y buy un u ibubibibu