Final answer:
The Enterprise plan is the most suitable for meeting the given requirements.
Step-by-step explanation:
The AWS support plan that will suffice to keep in mind the given requirements is the Enterprise plan. This plan provides 24x7 access to Cloud Support Engineers via email, chat, and phone, ensuring that the company's support needs are met at all times.
Additionally, the Enterprise plan guarantees a response time of less than 1 hour for any business critical system faults, which aligns with the specified requirement.