You get a message from a friend via Whatsapp claiming they are short of money and need to buy Christmas presents for their family. They ask you if you can lend them some money and they will pay you back as soon as the holidays are over. They provide you with their account number and sort code so you can do a bank transfer.
The answer was A and C
The only way you will know if it's genuine is if you phone them directly. Scammers can hack social media accounts and easily send messages from those accounts so they appear genuine. Because of this, you should never just reply to the message as you could be talking to the scammer.
Guide to fraud prevention
How to protect yourself against fraud