IELTS sample test: Identifying writer's views, why question 4 is NO?

Solution 1:

The answer NO is wrong.

Even without using the outside knowledge that cancer does not cause 100% of the deaths in the United States, the answer should be NOT GIVEN.

Why? The reading mentions that smoking contributes to heart disease, but it doesn't give any statistics. So to get the total percentage of deaths caused by smoking, you need to take 30% of the deaths by cancer, and add the deaths from smoking-related heart disease and other smoking-related diseases. (In fact, looking at the statistics, the deaths caused by smoking-related cancer are slightly less than half the total deaths caused by smoking.)