You are correct in selecting "linear pairs" since they form a straight line.
The angles are also adjacent because they're next to each other like that. In fact, "linear pair" means "adjacent and supplementary".
The angles are <u>not</u> complementary because they don't add to 90 degrees. Instead, they add to 180 degrees so that's what makes them supplementary.
The angles are also <u>not</u> vertical angles. They would need to be opposite one another in an X configuration for this to happen. This means vertical angles cannot be adjacent, and vice versa.
