Where are the central plains in the Midwest? along the Ohio River
along the Mississippi River
along the Great Lakes
along the Missouri River

b. after i get up in the morning,

explanation:

after is a subordinating conjunction that introduces a time clause. time clauses are dependent clauses used to indicate when something happened.

the clause "after i get up in the morning" tells when the action in the main clause (drinking a cup of coffee) happens:

"after i get up in the morning, i drink a cup of coffee." it is the most logical choice of all.