Which concepts are being ignored in each of the following scenarios?

(a) Inventory is valued at selling price given that the business has never failed to sell its inventory.

(b) A sole trader decides to include the petrol costs in full as business expenses despite some of the mileage being for personal use.

(c) A similar business has recently been sold for £80,000 more than the book value of the net assets. As a result, the owner of a business wishes to include goodwill in the non-current assets at a similar value to reflect the belief that the business is worth more than its net assets.

(d) Including a sale to a regular customer before the order is received.