Interestingly, the question really doesn't address weight bearing. I think it is assumed that with healthy upper body (to grab the rail &/or crutch) and one strong leg, the patient can do whatever type of WB'ing is required. The answer is indeed number 1.
The next question of this senerio is:
Your patient is discharged home, and follows up 4 weeks later with his surgeon. He then attends his physiotherapy session with you using a cane.
He shows you the note from the Surgeon that states "PWB up to 50%". How do you instruct this patient regarding change to his gait:

1. Put cane fwd first then left leg then right
2. Put right leg forward first, then left then cane
3. Put left leg forward first, then right then cane
4. Firmly explain why this referral means he must continue with crutches.