When connecting two independent clauses (clauses with a subject and verb that can stand alone), you need to use a conjunction or a semicolon like in the third sentence. This one has the comma, but neither of those, <u><em>so</em></u> it is incorrect. (see what I did there? I used a conjunction to connect my two independent clauses! B) )
All of these answers are punctuated correctly. I'm in advanced English and I know these are all right. I double-checked on Grammarly and a punctuation website that checks your sentences, Ginger.
