Which stretch do you think is the most importent if you have only one minute?

The stretch that I’ve been doing through out this challenge that I really come to enjoy was probably the plank. I know it’s not the most relaxing stretch, but it’s a stretch that builds strength and confidence in one’s self. I think it builds onto my goal, which is building a stronger body (or specifically abdomen). As I do it each day, I get stronger and stronger.