Answer:
Option B is correct.
The net ionic chemical reaction when Cu(NO₃)₂ reacts with water is
Cu²⁺(aq) + H₂O(l) ⇌ Cu(OH)¹⁺(aq) + H¹⁺(aq)
Explanation:
When ions dissolve in polar solvents (in water especially), then often attract ions of opposite signs.
Cu(NO₃)₂ dissolves into Cu²⁺ & NO₃⁻ and water contains H¹⁺ & OH⁻
The Cu²⁺ attracts the OH⁻ from water, thereby giving the Cu(OH)¹⁺ ion (with a net charge of +2-1 = +1) and the NO₃⁻ takes up the H⁺ ion.