r filter by group multiple critera

Question

I have a dataset with student scores. There are a lot of repeat rows per student ID like this below.

       ID    Date       Score    Source
       1     2016-02-24 19.2     A
       2     2020-01-08 16.6     B
       3     2021-01-25 18.1     A
       3     2021-01-25 16.2     C
       4     2011-02-28 13.2     A
       4     2011-02-28 17.4     A
       5     2011-02-28 19.2     A
       5     2011-02-28 14.6     C
       6     2016-04-16 11.2     C
       6     2016-04-16 12.4     C

My goal is to exclude some repeat observations and retain only observations based on this criteria.

Rule 1 : Same ID, Same date, different source. Retain only rows where Source = A Example ID 3, 5 , retain row

      3     2021-01-25 18.1     A
      5     2011-02-28 19.2     A

Rule 2 : Same ID, Same date, same source. Retain rows with max of score.

     4     2011-02-28 17.4     A
     6     2016-04-16 12.4     C

The final expected dataset

      ID    Date       Score    Source
       1     2016-02-24 19.2     A
       2     2020-01-08 16.6     B
  
       3     2021-01-25 18.1     A
      
       4     2011-02-28 17.4     A
  
       5     2011-02-28 19.2     A
        
       6     2016-04-16 12.4     C

I am aware of groupby and filter but I am not sure how to apply those functions in this situation. Any suggestion is much appreciated thanks.