How do you create a cached thread pool?

A$.$

ExecutorService executor $=$ Executors.newCachedThreadPool$()$;

B$.$

ExecutorService executor $=$ Executors.newCachedThreadPool$(2)$;

C$.$

ExecutorService executor $=$ Executors.newCachedThreadPool$(3)$;

D$.$

ExecutorService executor $=$ Executors.newCachedThreadPool$(1)$;