As a network engineer, you are tasked to develop an IP addressing schema that ensures a high number of available subnets while maintaining a sufficient number of host addresses per subnet. Which of the following CIDR notations BEST accommodates these requirements, considering a balance between subnet quantity and adequate address space per subnet?
/20 - 4094 hosts
/21 - 2046 hosts
/23 - 510 hosts
/25 - 126 hosts
/30 - 2 hosts