The number of scented candles packaged in a box can vary by at most two from an average of 80 candles per box. if the cost of producing a candle is two dollars, what is the range of the possible production costs, x, for 50 boxes of candles?
a. 78 ≤ x ≤ 82
b. 156 ≤ x ≤ 164
c. 3,900 ≤ x ≤ 4,100
d. 7,800 ≤ x ≤ 8,200