How will you make sure that a single instance of any Service is available throughout the app?

How will you make sure that a single instance of any Service is availa

1.	How will you make sure that a single instance of any Service is available throughout the app?
Answer» How will you make sure that a single instance of any Service is available THROUGHOUT the app? Choose the CORRECT option from below list (1)Register the service using 'imports' and ADD it to the Root Component (2)Register the service using 'providers' and add it to the Root Module------------- (3)Declare the service in the Root Component (4)None of the options Answer:-(2)Register the service using 'providers' and add it to the Root Module