Maths multiple choice question?

Each week, a company can sell x units of its product at a price of p dollars each,

where p = 250 - 4x. The total cost of producing x units is 4800 - 70x. Note that

revenue is equal to price times quantity. What quantity or quantities should the

company produce if it aims to break even?

(a) 20 units;

(b) 60 units;

(c) 20 or 60 units;

(d) 40 units.