Ava's best friend has an indoor cat. Ava notices that she sneezes every time that she visits her friend. Ava suspects that she is
allergic to cats but is unsure. What is the best thing for Ava to do next?
Stop visiting her friend.
Conclude that she is allergic to cats, and avoid them completely.
Test her suspicion by checking to see whether other cats also make her sneeze.
Assume that the sneezing has another cause, and reject her original idea.