You have five variables: X, Y, R, S, and T. The statements: 1. X affects Y. 2. R affects X and does not affect Y directly. 3. S affects Y and does not affect X directly. 4. T is caused by X and also caused by Y. 5. There are no other connections except those described (or their implied transitive consequences). Consider these claims: 1. R cannot be a confounder because it doesn’t directly affect Y. 2. S might be part of a backdoor path from X to Y only if there is some unobserved link from X to S. 3. T is a collider for X and Y. 4. Conditioning on T could introduce bias between X and Y. 5. Conditioning on R might have no impact on the backdoor path from X to Y. Which combination is correct?