Answer:
d) zero sum game.
Explanation: A zero sum game is such as gambling or lottery, where the net effect is equal to zero. In zero sum game, the total amount earned by one or more persons is directly proportional or equal to the sum of the contribution of every other participants in the game, leading to a ZERO SUM.
AS THE TEACHER COLLECTS $1 FROM EACH STUDENT AND GIVES IT BACK TO EACH STUDENT AT THE END OF THE YEAR, THE NET EFFECT OF THE GAME IS A ZERO, WHICH MEANS INPUT IS EQUAL TO OUTPUT.