Answer:
Option (D) i.e., s1.getClassRank( ); is the correct option to the following question.
Step-by-step explanation:
Here, in the following option, the object "S1" is the object of the class "rank" and "getClassRank( )" is the function of that class "rank". so, in the following code the function "getClassRank( )" is called through the class object which computes and returns the class rank of the students.
So, that's why the following option is the correct way to call the function.