Which example would most likely be considered an unethical business behavior?

Carl called in sick to work when he had the flu even though he had a project due.

Betsy clocked in to work and then got on the internet to check her workrelated e$-$mail.

Tom deleted files from his computer that were $5$ years old and no longer needed.

Jonathan worked $3\mathrm{.}2$ hours on a project and billed his company for $4$ hours.