Which sentence combines these two sentences and includes a relative clause?
The cashier rang up the manager's order. The cashier began working today.
The cashier who began working today rang up the manager's order.
The cashier rang up the manager's order because she began working today.
The cashier ringing up the manager's order just began working today.
The cashier rang up the manager's order, yet she began working today.
PLEASE HELP ASAP!!