Determine the number of subshells in the following: first shell, second shell, and third shell.

The first, second, and third shells all contain one subshell.

The first shell contains one subshell.
The second shell contains two subshells.
The third shell contains three subshells.

The first shell contains two subshells.
The second shell contains three subshells.
The third shell contains four subshells.

The first shell contains three subshells.
The second shell contains two subshells.
The third shell contains one subshell.