Which of the following variables are best thought of as continuous, which discrete? Indicate your choice for each by checking the appropriate column.

Variable Discrete Continuous (a) The total number of goals scored by a soccer team in a season (b) The highest grade level (9,10 , or11 ) completed by a high-school dropout (c) The number of damaged chromosomes on a petri dish following irradiation (d) The amount of coffee in a cup dispensed by a coin-operated coffee machine