Marcus defines a friend as "someone you can trust with your secrets and who will help you out when you need support." He understands that to have friends, one also needs to be a good friend to others. Based on Selman's view of friendship development, your best guess is that Marcus is about ___ years old and is in Stage ___ of Selman's theory.
◦ 6; 3
◦ 11; 3
◦ 16; 6
◦ 9; 6