which is the correct way to combine the sentences into one sentence with a compound subject? seagulls sat along the pier. sandpipers sat along the pier. a. seagulls and sandpipers sat along the pier. b. seagulls sat along the pier with sandpipers. c. seagulls sat along the pier, and sandpipers sat along the pier. d. seagulls sat and sandpipers sat along the pier.