Which is more effective for a successful business if the sale price of a marketed products is a) fixed price, or b) negotiate price, or c) auction price?

I think option a or b. Fixed price inclusive of all costs and profit margin will help in better control and profit. Secondly negotiable price with a margin of flexiblity will also help in better negotiation and customer satisfaction.

The option a) fixed price is more effective for successful business.Because,both customer and business person are more busy in the modern world.They have no enough time to burgaining or atttend in auction sale.Fixed price also help the customer to quick choose products and buying decision within short time.

can be answer b or c

It varies according to market segment and the product category. If its a high end market option a and option b is suitable. In middle class and lower income option b is mandatory unless its an essential product. Likewise if the brand is established and considered as essential Fixed Price can be charged. For generic products price should be negotiable to be competitive in the market.