A company is building a new web platform where user requests trigger an AWS Lambda function that performs an insert into an Amazon Aurora MySQL DB cluster. Initial tests with less than 10 users on the new platform yielded successful execution and fast response times. However, upon more extensive tests with the actual target of 3,000 concurrent users, Lambda functions are unable to connect to the DB cluster and receive too many connections errors.
Which of the following will resolve this issue?

A. Edit the my.cnf file for the DB cluster to increase max_connections
B. Increase the instance size of the DB cluster
C. Change the DB cluster to Multi-AZ
D. Increase the number of Aurora Replicas