Answer:
Cheryl, Heather and Keaton all are correct.
Step-by-step explanation:
Everything around you is made of matter and matter is anything that has mass and occupies space or in other words, anything which has volume is called matter.
Here, in the given example, Cheryl, Heather and Keaton all are correct because the mug, the hot chocolate which is inside the mug and the steam coming out of it, all have mass. Therefore, all are correct except for Mikayla.