A retailer purchased silk camisoles each costing $$21.$ When displayed on floor, the retailer marked the primary colours $($red$,$ yellow, blue$)$ at $$28$ a piece, pastel colours at $$32$ a piece and the black and white camisoles at $$35$ a piece.

Which pricing method is the retailer following?

Question $24$ options:

price skimming

price penetration

price lining

odd$-$even pricing