Cost ($) 200- 180- MC 160- 140- 120 ATC 100- 80- AVC 60- 40- 20 4 6 8 10 12 14 16 18 20 22 Q/t The graph shows cost functions for a firm (MC = marginal cost, ATC = average total cost, AVC = average variable cost). The total variable cost of sixteen units of output is a) impossible to estimate from the graph. O b) about $1.312 O c) about $400 O d) about $82