1st movement error calamity!
You REALLY don't want to make this mistake!!
Ever forgotten to halt on your entry up the centre line??
Or perhaps halted at X when you’re not supposed to??
If the bell (or horn) goes you’ll get that horrible realization of what you’ve done wrong, and I feel for you. BUT… please don’t then leave the arena at the earliest place and enter the arena again at A. Instead, trot on the outer track inside the arena and turn up the centre line and do it correctly.
Why?? Because the test has started when you enter and you only went wrong when you forgot to halt (or vica versa). So if you leave the arena and trot all the way round again, the letter of the law states elimination. You’ll be doubly pi…d off if that happened!!