What do these two changes have in common?
an iceberg melting slowly
carving a piece of wood

 - Both are caused by cooling.
 - Both are chemical changes.
 - Both are caused by heating.
 - Both are only physical changes.
Step 1: Think about each change.
An iceberg melting is a change of state. So, it is a physical change. An iceberg is made of frozen water. As it melts, the water changes from a solid to a liquid. But a different type of matter is not formed.
Carving a piece of wood is a physical change. The wood changes shape, but it is still made of the same type of matter.
Step 2: Look at each answer choice.
Both are only physical changes.
Both changes are physical changes. No new matter is created.
Both are chemical changes.
Both changes are physical changes. They are not chemical changes.
Both are caused by heating.
An iceberg melting is caused by heating. But carving a piece of wood is not.
Both are caused by cooling.
Neither change is caused by cooling.