A manufacturer sells $$\frac{8}{?}$ unit to wholesalers who mark up by $25\%$ on manufacturer selling price. Afterwards, the retailers mark up by $33\mathrm{.}33\%$ on consumer purchase price. Here,

wholesaler markup is based on cost$,$ retailer markup on selling price

both wholesaler and retailer markup are based on selling price

wholesaler markup is based on selling price, retailer markup on cost

All the other $4$ answers are correct.