Which two solutions can an Architect recommend to resolve the bottleneck and improve performance?

A client runs an application on a background worker dyno. The application allows its users to request personalized information as a PDF. At peak usage, the app processes millions of requests at once. The resulting numberof requests has caused a bottleneck that is impacting its performance.

Which two solutions can an Architect recommend to resolve the bottleneck and improve performance? (Choose two.)
A . Increase the number of workers to consume the job faster.
B . Move the application to a Private Space.
C . Add Heroku Redis as a job queue.
D . Add a CDN add-on from the Elements marketplace.

Answer: A, C