Answer:
The correct option is A.
Step-by-step explanation:
Let the price of a helmet is x, the price of a bat is y and the price of a ball is z.
It is given that Company A can provide 9 helmets, 6 bats, and 12 balls for $525. The equation for Company A is

It is given that Company B can provide 10 helmets, 8 bats, and 10 balls for $600. The equation for Company B is

It is given that Company C can provide 8 helmets, 5 bats, and 15 balls for $500. The equation for Company C is

The system of equations is



Therefore the correct option is A.