What is the difference between shutil.copy$()$ and shutil.copytree$()?$

Question $9$ options:

shutil.copy$()$ copies a single file, while shutil.copytree$()$ copies an entire directory.

shutil.copy$()$ and shutil.copytree$()$ both copy single files.

shutil.copy$()$ copies an entire directory, while shutil.copytree$()$ copies a single file.

There is no difference between shutil.copy$()$ and shutil.copytree$().$