the minimum of their average-total-cost curves

all of these answers are correct.

their efficient scale.

zero economic profit.

implicit costs

variable costs

the sum of implicit and explicit costs.

explicit costs.

variable costs

implicit costs

explicit costs.

marginal costs.

Rs. 30,000

Rs. 35,000

Rs. 70,000

Rs. 75,000

is linear (a straight line).

is negative throughout its length

becomes steeper as the quantity of output increases.

becomes flatter as the quantity of output increases