p(1)=1+a+b+2=0, so a+b=−3. p(−2)=−8+4a−2b+2=0, so 4a−2b=6, i.e., 2a−b=3. Add: 3a=0⇒a=0, b=−3. Wait, a+b=−3 with a=0 gives b=−3. But choice says −1. Recompute: 2a−b=3 with a=0 gives b=−3. Hmm. Adjusting: actually with a=0, the polynomial is x3+bx+2. With b=−3: p(1)=1−3+2=0 ✓; p(−2)=−8+6+2=0 ✓. So correct b=−3.