Which AWS service or feature should be used to host the application in the AWS Cloud?

Explanations:

Amazon EC2 Standard Reserved Instances require long-term commitment (1 or 3 years) and are best suited for predictable workloads that run continuously, making them less suitable for workloads with varying usage patterns like this one.

Amazon EC2 On-Demand Instances provide flexibility to scale based on demand, which is ideal for applications that run periodically with varying usage patterns, as in this case where the application runs for a few hours most days and for 8 hours a day for a week at the end of each month.

AWS Wavelength is designed for ultra-low latency applications that require edge computing closer to end-users. It is not suitable for periodic workloads that run in a cloud environment.

An Application Load Balancer is used to distribute incoming application traffic across multiple targets, such as EC2 instances. It is not a service for hosting applications directly.