Which of the following usually stores all user related data that is also relevant to GSM mobile syst...........

Explanation:

Answer: d
The device that usually stores all the user-related data relevant to the GSM mobile system is known as the SIM Card. A SIM Card is a kind of integrated circuit that securely holds the IMSI (or International Mobile Subscriber Identity). It can also be considered as a portable memory chip that enables users to communicate by making phone calls across the world where the subscriber's network is available.