An Ecommerce Company Has an Order Processing Application It Wants

An ecommerce company has an order processing application it wants to migrate to AWS. The application has inconsistent data volume patterns, but needs to be avail at all times. Orders must be processed as they occur and in the order that they are received. Which set of steps should a solutions architect take to meet these requirements?

A) Use AWS Transfer for SFTP and upload orders as they occur. Use On-Demand Instances in multiple Availability Zones for processing.
B) Use Amazon SNS with FIFO and send orders as they occur. Use a single large Reserved Instance for processing.
C) Use Amazon SQS with FIFO and send orders as they occur. Use Reserved Instances in multiple Availability Zones for processing.
D) Use Amazon SQS with FIFO and send orders as they occur. Use Spot Instances in multiple Availability Zones for processing.