How should read, write and execute permissions for ‘group’ and ‘other’ be gr

How should read, write and execute permissions for ‘group’ and ‘other’ be granted to all files and
directories within the /app filesystem?

A.
chmod -R 677 /app

B.
chmod -R 664 /app

C.
chmod -r 677 /app

D.
chmod -r 664 /app