GAMSAT Physics Q: Can't Understand Answer? Get Help Here!

[luysion]

http://prepgenie.co.nz/gamsat/gamsat-questions/gamsat-sample-physics/
hey there's a question here if you scroll down a bit, i don't understand how the answer is C
can you please explain this to me cheers, and much appreciation to any that help.

:)

 

[!kx!]

You sure answer is C.. If we assume pulley is at rest.. by me it should be B, 240/7 N..

EDIT: And the pulley does seem at rest in image (it didn't download earlier!)