Correct Option (c)
Digital Subscriber Line (DSL) does not belong to the GSM family of wireless technologies. DSL is a wired broadband technology that provides internet access over traditional copper telephone lines. It is a fixed-line communication standard and is distinct from mobile wireless communication protocols like GSM (Global System for Mobile Communications).
Incorrect Options:
EDGE (Enhanced Data Rates for GSM Evolution) is an upgrade to GPRS within the GSM standard. It is classified as a 2.75G technology, offering improved data transmission rates for GSM networks. Therefore, EDGE is an integral part of the GSM family.
LTE (Long Term Evolution) is a 4G wireless broadband technology. While it utilizes a new radio interface, it is widely recognized as a significant evolutionary step from earlier GSM-based standards such as UMTS (3G) and HSPA (3.5G). LTE represents the progression of the GSM ecosystem towards higher data speeds and network capacity.
Since both EDGE and LTE are part of the GSM family or its evolutionary path, options (a), (b), and (d) are incorrect.