For a particular level of output, the least costly way to produce the output occurs 0 a, where the isoquant crosses the isocost line that is the farthest to the right b. where the isocost line intersects the origin. c. at the point where the isocost line is the greatest distance from the isoquant. d. at the point of tangency of the isocost line and the isoquant.

D. At point of tangency of Isocost & Isoquant

Explanation:

Isocost is graphical presentation of factor inputs ,which have same total cost/ same budget for producer . It is analogous to Consumer Budget Line (goods combinations , given income & price) .

Isoquant is graphical presentation of factor inputs , which give producers same level of output. It is analogous to Consumer Indifference (goods combinations giving same satisfaction level)

Both the curves are downward sloping as : Given same cost , same output - if one factor has increased , other must have decreased & vice versa . However-  Isocost is straight line having constant slope = price ratio of two factors , Isoquant is convex shape because of falling slope = Marginal Rate of Technical Substitution.

Producer Equilibrium : Isocost Line is tangent to Isoquant Curve & there slopes are equal . The former one represents Cost Minimzation & the latter one Profit Maximisation . Any deviation from this equilibrium state will either reduce output at that cost , or increase cost of the same output.

they can see what that city is producing and to also see if they can some how get that product. like gold in africa.