Which problem can be solved using this equation? 0.15m+35=0.25m+20

A-One phone company charges $35.15 per minute.
The other phone company charges $20.25 per minute.
For how many minutes, m, do the companies charge the same amount?

B-One phone company charges a flat fee of $0.15, plus $35 for each minute.
The other phone company charges a flat fee of $0.25, plus $20 for each minute.
For how many minutes, m, do the companies charge the same amount?

C-One phone company charges a flat fee of $35, plus $0.15 for each minute.
The other phone company charges a flat fee of $20, plus $0.25 for each minute.
For how many minutes, m, do the companies charge the same amount?