P, Q, R and S are metals. P reacts with dilute hydrochloric acid, and hydrogen is produced. Q reacts very violently with water. R reacts with water, giving hydrogen. S is produced by heating its oxide with carbon. Which row gives the correct identities of the metals?
- AP: copper; Q: sodium; R: potassium; S: iron
- BP: zinc; Q: magnesium; R: calcium; S: iron
- CP: zinc; Q: sodium; R: calcium; S: magnesium
- DP: iron; Q: potassium; R: sodium; S: zinc