Why does the marginal cost curve intersect the average total cost (ATC) curve at the ATC curve’s minimum point? Provide an explanation for this phenomenon.

a. Because marginal cost (MC) and average total cost (ATC) must eventually converge
b. Due to the relationship between total cost, fixed cost, and variable cost
c. As a result of economies of scale and diseconomies of scale
d. Because the slope of the MC curve equals the slope of the ATC curve at their intersection