AMC 10B 2017 Problem 3

Real numbers x, y, and z satisfy the inequalities

0<x<1, \quad-1<y<0, \quad \text { and } \quad 1<z<2

Which of the following numbers is necessarily positive?

Answer Choices
A. y+x^{2}
B. y+x z
C. y+y^{2}
D. y+2 y^{2}
E. y+z