ᴘᴇʀᴘᴇᴛᴜᴀʟ ɪ ʙᴇʟɪᴇᴠᴇ ʙᴜᴛ ɪᴍ ɴᴏᴛ sᴏ sᴜʀᴇ
A bag is the indefinite article so i would guess c
When needing advice about something. Like if someone watched their mom get hit by a friend. The one that watched their mom get hit should be able to talk to a friend about what to do next.