31) A
1 – Correct
Aspiring can reduce the risk of further trouble after heart attack but it can also induce internal bleeding and carries a slight risk of cerebral haemorrhage. So it is a matter of balancing risks and benefits.
2 – Wrong
80% reach the threshold by 50. The other 20% do not. so we cannot conclude statement 2.
3 – Wrong
No information is given about the relative risk of heart attack in men aged 40 compared to men aged 50.
Since only statement 1 is correct, A is the answer.