How do you prevent DNS spoofing?

Let’s imagine three companies (A, B and C), all competing in a challenging global environment. Company A and B are working together in developing a product that will generate a major competitive advantage for them. Company A has a secure DNS server while company B has a DNS server vulnerable to spoofing. With a spoofing attack on the DNS server of company B, company C gains access to outgoing e-mails from company B.

How do you prevent DNS spoofing?
A . Install DNS logger and track vulnerable packets
B . Disable DNS timeouts
C . Install DNS Anti-spoofing
D . Disable DNS Zone Transfer

Answer: C