Your company is planning to pay for an AWS Support plan. They have the following requirements as far as the support plan goes:
24x7 access to Cloud Support Engineers via email, chat & phone
Response time of less than 15 minutes for any business-critical system faults
Which of the following plans will suffice to keep in mind the above requirement?

Answer options:

A.Basic
B.Developer
C.Business
D.Enterprise

Answer – D
As per the AWS document, there is no critical support available for Basic, Developer and Business plans. 
Enterprise plan has critical support within 15 minutes. The question mentions less than 15 minutes for critical faults. Hence the correct answer is Enterprise. 
For more information on the support plans, please refer to the following Link:
https://aws.amazon.com/premiumsupport/compare-plans/