You must put a loaded bus into motion from a stopped position on a steep upgrade (4% or more). Which of these is the best technique to follow when you have a bus with a manual transmission?

"Don’t roll back when you start. You may hit someone behind you. If you have a manual transmission vehicle, partly engage the clutch before you take your right foot off the brake. Put on the parking brake whenever necessary to keep from rolling back. Release the parking brake only when you have applied enough engine power to keep from rolling back."