C# - closing Sql objects best practice

Question

If you have a C# function with Sqlaccess, is it mandatory to close all objects/handles, or is everything cleaned up automatically once you exit the function

For exam

Answer 1

Calling Close on the SQL connection won't actually close it, but will return it to a connection pool to be reused, improving performance.

Additionally it is generally poor practice to not explicitly dispose of unmanaged resources when you are finished with them (asap).