Final answer:
AES is a type of symmetric encryption algorithm.
Step-by-step explanation:
AES (Advanced Encryption Standard) is a type of symmetric encryption algorithm. It is widely used to secure sensitive data in various applications, such as online banking and communication protocols.
The other options mentioned are not symmetric encryption algorithms. MD5 is a hash function, SYM does not appear to be a recognized encryption algorithm, and SSL (Secure Sockets Layer) is a cryptographic protocol used to provide secure communication over the internet.