Enabling Mutual TLS (mTLS) for all internal traffic (Gateway -> Service) increases CPU utilization and increases latency. What part of the TLS lifecycle is the primary bottleneck at high scale?

1. A The symmetric encryption of the data packets (AES-GCM), which requires massive algorithmic work for every byte sent.
2. B The memory overhead of holding the TCP socket open for the duration of the transfer.
3. C The asymmetric cryptographic handshake, specifically the cost of RSA/ECC private key operations to prove identity for every new connection.
4. D The time spent by the OS kernel verifying the file system permissions of the certificate files.