Tranjia Is an African City Where the Residents Have Limited

Tranjia is an African city where the residents have limited access to a bank. They prefer to use a phone-based money transfer system. Using this system, residents of Tranjia can deposit, withdraw, and transfer money within seconds. They can also use this system to purchase and pay for goods. In this scenario, which of the following is the phone-based money transfer system that the residents of Tranjia are most likely using?

A) M-Pesa
B) MetLife
C) Upstart
D) Zenfolio