What do these two changes have in common?
a slice of banana turning brown
burning food on a stove

 - Both are caused by cooling.
 - Both are only physical changes.
 - Both are chemical changes.
 - Both are caused by heating.
Step 1: Think about each change.
A slice of banana turning brown is a chemical change. The part of the banana in contact with the air reacts with oxygen and turns into a different type of matter.
Burning food on a stove is a chemical change. When the food burns, the type of matter in it changes. The food turns black and gives off smoke.
Step 2: Look at each answer choice.
Both are only physical changes.
Both changes are chemical changes. They are not physical changes.
Both are chemical changes.
Both changes are chemical changes. The type of matter before and after each change is different.
Both are caused by heating.
Burning is caused by heating. But a slice of banana turning brown is not.
Both are caused by cooling.
Neither change is caused by cooling.