Answer:
Option d is correct.
Step-by-step explanation:
Discrete values are those which take an integer value not in fraction.
Option A is discrete because there will be certain number of students in class say 20 or 30
We can not have 20.5 students
Therefore, option a is correct.
Option B is not discrete because many people can have age say 65 and a half years and weight can be in decimals say 50.5 kgs.
Option C is correct because he is saving a proper integer number of money.
Therefore, option d is correct that is both A and C are correct.