You have inherited a VPC which has a CIDR of 10.0.0.0/16. You need to design a subnet layout which allows for four availability zones to be used. Which option below is valid for this criteria? Pick the one which uses the least number of subnets to decrease management overhead.

A. Create a single subnet, 10.0.0.0/16, which spans all four availability zones. B. Create four subnets: 10.0.0.0/24, 10.0.1.0/24, 10.0.2.0/24 and 10.0.3.0/24, and put each one in its own availability zone. C. Create two subnets, 10.0.0.0/24 and 10.0.1.0/24, and set each subnet in an HA configuration. Set each subnet to use two of the four availability zones. D. Create four subnets, all using the 10.0.0.0/16 range, and put each subnet into its own availability zone.