The first and third one are correct. The middle one is fiction.
        
             
        
        
        
Answer:
We can walk to the park, or we can drive the car.
Explanation:
 
        
             
        
        
        
Did the leader of project healing waters attend the U.S. Naval Academy in Annapolis?
        
             
        
        
        
The answer is A. Mercedes threw Andrea, Mercedes' best friend, a surprise party last night.  This choice uses an appositive ("Andrea, Mercedes' best friend,") to combine the two sentences.  An appositive is a phrase separated from the rest of the sentence by commas that describes something (in this case Andrea).
Choices B and C are incorrect because the uses of the words "but" and "when" to combine the sentences do not make logical sense.  Choice D is incorrect because it uses a comma to combine the sentences without a conjunction, creating a run-on sentence.
Hope this helps!