Choice "D" is correct. The net gain from the sale of a warehouse and purchase of a new warehouse will fall under continuing operations on the income statement, under "other" revenues and gains.
Choice "c" is incorrect. The fact that the proceeds exceeded the carrying amount of the warehouse sold would not serve to reduce the cost basis of the new warehouse.
Choice "b" is incorrect. The sale of a warehouse and consequent replacement with a new warehouse do not qualify as discontinued operation.
Choice "a" is incorrect. This transaction does not meet the unusual and infrequent criteria of an extraordinary item.