The Developer team has launched a new gaming application that uses the Amazon Cognito user pool to provide user authentication. The team is looking for the number of users who are successfully authenticated and using this application.
Which Amazon Cognito user pools metric can be checked to get the required details?

Answer options:

A.SignUpSuccesses
B.SignUpThrottles
C.SignInSuccesses
D.SignInThrottles

Correct Answer: C
SignInSuccesses metric provides a total number of successful user authentication requests made to the Amazon Cognito user pool. 
User authentication is considered successful when an authentication token is issued to the user. A successful authentication produces a value of 1, whereas an unsuccessful request produces a value of 0. A throttled request is also considered as an unsuccessful request, and hence a throttled request will also produce a count of 0.
Option A is incorrect as the SignUpSuccesses metric can be used to get the total number of successful user registration requests made to the Amazon Cognito user pool. But it will not provide the total number of successful user authentication requests made to the Amazon Cognito user pool.
Option B is incorrect as the SignUpThrottles metric can be used to get the total number of throttled user registration requests made to the Amazon Cognito user pool, which does not fulfill the requirement of the total number of successful user authentication requests.
Option D is incorrect as the SignInThrottles metric can be used to get the total number of throttled user authentication requests made to the Amazon Cognito user pool. But it will not provide the total number of successful user authentication requests made to the Amazon Cognito user pool.
For more information on metrics for Amazon Cognito user pools, refer to the following URL,
https://docs.aws.amazon.com/cognito/latest/developerguide/metrics-for-cognito-user-pools.html