Which sentence uses a semicolon correctly?

the cashier gave lila change; but it was the incorrect amount.
linsey wanted to see a movie whereas; marla wrote her sister a letter.
although mike’s soccer practice is on monday; the first game is next tuesday.
john sat down in his seat just in time; the class bell had just rung.

John sat down in his seat just in time; the class bell had just rung.

Explanation:

The first three have a transitional word, (but, whereas, although).  So, they do require a semicolon.  The last option has two independent phrases seperated by a semicolon.  It is therefore, the correct option.  

the answer is:

apprehensive.

what are the phrases to choose from?