Back to the gmat land after a few weeks off. Hope I am not rusty....

Stmt I

y = |x| + x

y is 0 if x is 0 or x<0

Stmt I

x<0

Exactly what we need => y is 0 since |x| = -x when x is negative i.e |x|+x = -x + x which is 0 when x is negative

SUFF

Stmt II

y<1
Since y is an integer therefore x is 0 or x<0

SUFF

Choose D