400 m run takes roughly 2 min.
It's best if you are operating at a level 7 out of 10 intensity.
If you like, you may swap the 2 min cardio for 400 m run.
Today would be a good day to work on your cardio weaknesses. IOW do what you like for the cardio portion. Usually we like you to adhere strictly to the programming prescribed since our days build upon each other. Today, however, since you are not on the clock, and since your only measurement of success is to post "Done" you may switch the cardio portion at will. Just make a note of it to comments so you'll know how it affected you. Do not alt or sub other movements - unless you have specific needs.
Last thing. Watch those good mornings! They can leave you hobbling if you don't maintain a neutral spine throughout the movement. If you're not sure if you are maintaining a neutral spine, use the mirrors for help - OR ask a trainer/vet.