Simplify the following text for a Grade 10 native English-speaking person.
Original: The Line C had been extended to improve the access between the center of SÃ # o Paulo and southern region of the Greater SÃ # o Paulo including the circuit , improving circuit accessibility .
Simplified: The Line C had been extended to improve the access between the center of SÃ # o Paulo and southern area of the Greater SÃ # o Paulo including the circuit .