Four metals — zinc, M, copper and magnesium — are each put into aqueous solutions of their nitrates. The observations are given below. Legend: ✓ = reacts, ✗ = no reaction What is the reactivity order of these four metals, beginning with the most reactive?
- Acopper → zinc → M → magnesium
- Bcopper → M → zinc → magnesium
- Cmagnesium → M → zinc → copper
- Dmagnesium → zinc → M → copper