Reu decision notification

I got accepted into a program for psychology and I’m really excited and happy about it but they told me to notify them about my decision to decline or accept by march 1st. However, all the other reu programs I applied to would notify me with their decision March 1-mid April. I want to go to the program that accepted me if I knew I wasn’t accepted anywhere else, but if I knew I was accepted into the other reu programs I would select the other one. What could I do?