Thanks for the question! So we’re asked here for something we can properly infer from the passage.And so what are we told here? Well, the incidence of injuries has dropped, and the proportion of other ski-related injuries rose. Now take a look at (B), which says that the amount of alcohol consumed per skier increased between 1950 and 1980. We’re told that the incidence of these injuries goes up with the amount of alcohol consumed per skier. But that just means that when there’s more alcohol, there’s also more injuries. The alcohol can be one of the explanations for the higher incidence, but doesn’t necessarily have to be the only one. It doesn’t also mean that when there’s a higher injury incidence, there’s more alcohol being drunken. In other words, it tells us
More alcohol —> Higher injury incident of “those” injuries
And not
Higher injury incident of “those” injuries —> More alcohol
Hope this helps! Feel free to ask any other questions that you might have.