Which option is used in /etc/vfstab to limit the size of a tmpfs(7FS) file system to 512MB to preven

Which option is used in /etc/vfstab to limit the size of a tmpfs(7FS) file system to 512MB to prevent a memory denial of service (DoS)?

A.
size=1024k

B.
size=512m

C.
set size=512

D.
swapfs=512mb