Answer: Hello your required question is wrong as it does not tally with the data provided , attached below is the complete question
answer:
/23 /26 /27 /28 option A
Explanation:
Breakdown of the last four subnet masks given to the subnets
For the subnet of 500 production host the mask = /23 which will produce 512 hosts
For the subnet of 60 sales host the mask = /26 which will produce 64 hosts
For the subnet of 12 host the mask = /27 which will produce 32 hosts
For the subnet of 30 hosts the mask = /28 which will produce 16 hosts
