Which description is represented by a discrete graph?

Kiley bought a platter for $19 and several matching bowls that were $8 each. What is the total cost before tax?
The temperature at 9 a. m. was 83° F and is heating up at an average rate of 6°F per hour. What is the temperature x hours later?
Juan ate an egg with 78 calories and some cereal with 110 calories per serving for breakfast. What is the total amount of calories he consumed?
A bottle contained 2,000 mL of liquid and is being poured out at an average rate of 300 mL per second. How much liquid is left in the bottle after x seconds?