Please choose the correct ending to complete the given sentence: Computers and Electronics: [header] How to buy and sell safely online [title] After receiving payment via any method, you must authenticate the sending party to ensure that they authorize the transaction and they are whom they claim to be. [title] Ask for name, telephone, and address. [title] Use an online telephone directory such as 411.com and view their name and address.

Ending1: [title] Show the person your current address and/or telephone number (if you have one). [step] The email address should be listed, unless this is the only name listed. Ending2: [title] Enter your mobile phone number and the requested data into an open " authentication " app. [title] Tap the " i am authenticating your transaction " button. Ending3: [step] This information should match what you were provided with. [title] Call them, whether the information matches or not, this allows you to confirm the order. Ending4: [title] Gather all licenses and certifications, receipts and supporting documents related to the transaction. [title] Determine the type of payment you need in order to open your third party account.

Answer format: ending1/ending2/ending3/ending4