Which octal mode with the chmod command can Wally use to set these same permissions?

Wally created a new file named coursebook. The umask was set to the Solaris 10 default when
the file was created. Wally used the following command to change the files permissions:
$ chmod g+w ./coursebook
Which octal mode with the chmod command can Wally use to set these same permissions?

A.
chmod 662 ./coursebook

B.
chmod 660 ./coursebook