The answer to this question is : C. Hotmail Outlook
It is a mail client software which allows you to access or open your web email account. You can open as many email accounts as you want. But before you can connect a mail client to your email account , you have to configure ports and protocols first.
There are two types of connections needed to use for mail clients. Internet Message Access Protocol and Post Office Protocol. You can choose between those two. Post Office Protocol is a connection used for receiving incoming emails from your mail server accounts. Normally Post Office Protocol uses email URL and port number. The encryption or security connection implemented by Post Office Protocol is either SSL or Transport Layer Security.
Internet Message Access Protocol on the other hand is almost similar to Post Office Protocol, it is also for receiving mails. But emails you will be receiving in this type of protocol and connection will make your messages disappear on any device if you trigger the delete button. Unlike with Post Office Protocol, when you delete a message, it will be stored in your mail server but will disappear on your device.