What communication standard does GSM represent?

The correct answer is C, which stands for Global System for Mobile Communications. This communication standard is a widely adopted digital mobile telephony system that provides a means for mobile devices to communicate over a network. GSM was developed to ensure that mobile communication is standardized across different countries and networks, allowing interoperability and efficient radio frequency management.

GSM introduced important features such as digital voice encoding, advanced error correction, and support for SMS (Short Message Service). It laid the foundation for mobile networks and allowed for the development of additional technologies like GPRS (General Packet Radio Service) and EDGE (Enhanced Data rates for GSM Evolution).

While the other options might sound plausible, they do not accurately represent the GSM standard. Global Secure Messaging, Gigabit Standard for Multimode communications, and General Secure Mobile networks do not correspond to any recognized or established communication standards in the context of mobile communications. The focus of GSM is specifically on mobile telephony, which distinguishes it from these unrelated terms.