34) B

Questions states that 40% of study cohort consumed 14 units per week.
Study cohort = 10,000 participants
40% of 10,000 = 4000 participants

Out of these 4000 participants, 80 went on to develop dementia.
Proportion of people out of these 4000 that developed dementia = (80 ÷ 4000) = 0.02

Now, we know that 7 glasses of wine is 14 units
1 glass of wine therefore is 2 units
3 glasses is 6 units (this is per day as per the question).
Per week, this would be 6 x 7 = 42 units
If we read the graph, 42 units corresponds to a hazard ratio of approximately 1.5

Now we use the formula given in the passage.
We need to find out the proportion of participants that consumed 42 units per week in midlife who went on to develop dementia.

We know proportion of participants that consumed 14 units per week in midlife who went on to develop dementia = 0.02

We know 42 units corresponds to a hazard ratio of approximately 1.5

Screenshot 2021-06-14 at 09.56.27

0.03 = 3%