किसी वेबसाइट के पते में उपसर्ग 'https' का उपयोग मुख्य रूप से क्या दर्शाता है?

Which of the following statements are FALSE in the context of computer networks and security? A. A mail server is a computer that stores and forwards e-mail messages. B. File Transfer Protocol (FTP) is used to copy files from secondary memory to primary memory. C. Internet Relay Chat (IRC) enables users to copy files from one user to another user. D. Peer-to-Peer services allow users to access each other's computer via the Internet. E. In Instant Messaging, users can create their own chat rooms where invited guests can participate. Choose the correct option:

Consider the following four statements: S1: MD5 is vulnerable to the Birthday attack. S2: Traceroute uses the 'Destination port unreachable' ICMP error message. S3: AES is a type of public key encryption algorithm. S4: IPv4 has a maximum of 60 byte fixed header size. How many of the above statements are TRUE?