You want to ensure that instance in a VPC does not use AWS DNS for routing DNS requests as you want to use your own managed DNS instance. How can this be achieved?

Answer options:

A.Change the existing DHCP options set.
B.Create a new DHCP options set and replace the existing one.
C.Change the route table for the VPC.D.Change the subnet configuration to allow DNS requests from the new DNS Server.

Answer: B
Option A is incorrect because you cannot make changes to the existing DHCP options set.
Option B is CORRECT because, in order to use your own DNS server, you need to ensure that you create a new custom DHCP options set with the IP of the custom DNS server. 
Option C is incorrect because the route tables can only work with VPC routes and are not a custom DNS solution.
Option D is incorrect because to manage your own DNS instance, your need to work at the VPC level and not at the subnet level.
For more information on the DHCP options set, kindly refer to the URL below:
https://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/VPC_DHCP_Options.html