Delfina has $580 in her savings account and she has to pay $10 each month to her parents for her cell phone. Vicente has $260 and he saves $30 each month from his job walking dogs for his neighbor. At this rate, when will Delfina and Vicente have the same amount of money?
a) After 4 months
b) After 6 months
c) After 8 months
d) After 10 months