Which solution should be implemented?

An API developer is improving an application code to prevent DDoS attacks. The solution needs to accommodate instances of a large number of API requests coming for legitimate purposes from trustworthy services .

Which solution should be implemented?
A . Restrict the number of requests based on a calculation of daily averages. If the limit is exceeded, temporarily block access from the IP address and return a 402 HTTP error code.
B . Implement REST API Security Essentials solution to automatically mitigate limit exhaustion. If the limit is exceeded, temporarily block access from the service and return a 409 HTTP error code.
C . Increase a limit of replies in a given interval for each AP
D . If the limit is exceeded, block access from the API key permanently and return a 450 HTTP error code.
E . Apply a limit to the number of requests in a given time interval for each AP
F . If the rate is exceeded, block access from the API key temporarily and return a 429 HTTP error code.

Answer: D

Explanation:

Reference: https://www.whoishostingthis.com/resources/http-status-codes/