A student pours $10\ \text{cm}^3$ of $0.100\ \text{mol dm}^{-3}$ sulfuric acid into one test-tube and $10\ \text{cm}^3$ of $0.100\ \text{mol dm}^{-3}$ ethanoic acid into a second test-tube. He then adds $1.0\ \text{g}$ (an excess) of magnesium ribbon to each test-tube and records suitable measurements. Both acids start at the same temperature. Neither reaction is finished after 2 minutes, but both are complete after 20 minutes. Which of the following statements are correct?
- A1, 2 and 3
- B1 and 2 only
- C2 and 3 only
- D1 only