The following sentence contains a comma splice:
I work until nine o'clock on weeknights, my shift ends at midnight on Saturday.
Which revision corrects the sentence?
I work until nine o'clock on weeknights. My shift ends at midnight on Saturday.
I work until nine o'clock on weeknights, because my shift ends at midnight on Saturday.
I work until nine o'clock, on weeknights. My shift ends at midnight, on Saturday.
I work until nine o'clock on weeknights; but my shift ends at midnight on Saturday.