When the output is zero in the short run. Which of the following costs are undefined?

Option 1 -> AVC = VC/Q = 0/0 (indeterminate), AFC = FC/Q = FC/0 (undefined), MC cannot be calculated at zero output - all undefined.

Option 2 -> AFC is undefined but TC = FC (defined as fixed costs still exist).

Option 3 -> VC = 0 (defined, just zero), MC is undefined.

Option 4 -> Both TC and FC are defined even at zero output.

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Hence, Option 1: AVC, AFC and MC -> When output is zero, all average costs (AVC, AFC, ATC) involve division by zero and become undefined. Marginal Cost is also undefined at zero output because it represents the rate of change of cost with respect to output, which cannot be determined at the starting point. However, total costs (TC, FC, VC) remain defined - FC exists regardless of output, VC equals zero, and TC equals FC. -> correct