Symmetric encryption uses a single shared secret key for both encrypting and decrypting the data, which makes it fast but creates a specific practical difficulty.

Its main limitation is that key distribution and management become challenging: the same secret key must somehow be delivered securely to every party that needs it, and if it is intercepted during that exchange, the security is broken.

Managing keys also scales poorly, because as the number of communicating users grows, the number of unique shared keys required grows very quickly.

Symmetric algorithms are actually computationally light and fast, so they use fewer resources than asymmetric encryption — this makes the "requires more computational resources" option incorrect.

For the same reason, the claim that the encryption and decryption process is "too slow" is wrong; symmetric ciphers are well suited to encrypting large volumes of data quickly.

Symmetric encryption can certainly be used for data at rest, such as encrypting stored files and full disks, so that option is also incorrect.

Therefore the genuine drawback is the secure exchange and handling of the shared key, making the correct answer Key distribution and management become challenging.