The correct answer is: C. W-CDMA
W-CDMA (Wideband Code Division Multiple Access) is a third-generation (3G) cellular technology that was developed in Europe. It is a direct descendant of GSM (Global System for Mobile Communications), the most widely used 2G cellular technology in the world. W-CDMA offers a number of advantages over GSM, including higher data rates, greater capacity, and improved voice quality.
GPRS (General Packet Radio Service) is a 2.5G cellular technology that was developed to provide packet-switched data services over GSM networks. GPRS offers much higher data rates than circuit-switched data services, such as SMS (Short Message Service), but it is still slower than 3G technologies like W-CDMA.
HSCSD (High-Speed Circuit-Switched Data) is a 2.5G cellular technology that was developed to provide faster data rates over GSM networks. HSCSD offers up to four times the data rate of standard GSM, but it is still slower than 3G technologies like W-CDMA.
EDGE (Enhanced Data Rates for GSM Evolution) is a 2.75G cellular technology that was developed to provide even faster data rates over GSM networks. EDGE offers up to eight times the data rate of standard GSM, but it is still slower than 3G technologies like W-CDMA.
In conclusion, W-CDMA is the only option that leads to the 3G evolution of GSM, IS-136 and PDC systems.