What is the number of children and adults who attended the zoo if the admission fee for children is $1.50 and for adults is $3.00, and a total of 2500 people entered the zoo, collecting $5,850.00?
a) 1500 children and 1000 adults
b) 1000 children and 1500 adults
c) 1250 children and 1250 adults
d) 2000 children and 500 adults