9700/11 Biology May Jun 2017 Online Test | Cambridge AS and A Level MCQ

The graph shows the results of an investigation into the effect of amylase on starch at three different temperatures.
Which statements are correct conclusions using these results?
1) The optimum temperature is ${50^ \circ }C$.
2) The initial rate of reaction is highest at ${70^ \circ }C$.
3) The higher the temperature the more quickly the enzyme denatures.