The Following Sentences Form a Paragraph

Multiple Choice

The following sentences form a paragraph. For each set of choices, select the answer in which conjunctions or conjunctive adverbs are used correctly and the punctuation is correct. Which sentences are correct?

A) It follows exactly the river's path, or the river bends and twists its way into the city. A straight trip on city streets would be two miles shorter.
B) Because it follows exactly the river's path, the river bends and twists its way into the city. A straight trip on city streets would be two miles shorter.
C) It follows exactly the river's path, and the river bends and twists its way into the city. A straight trip on city streets would be two miles shorter.