The total cost of producing x items is given by ( C = 5x² - 3x + 300 ). Find the fixed cost and average cost function. Also, find the value of the total cost and average cost function at x = 10.
a) Fixed Cost: 500, Average Cost: (50x - 3), Total Cost: 800
b) Fixed Cost: 300, Average Cost: (5x - 3), Total Cost: 530
c) Fixed Cost: 300, Average Cost: (5x - 3), Total Cost: 830
d) Fixed Cost: 500, Average Cost: (50x - 3), Total Cost: 530