(a) Yes, hoarding is an example for the consumer exploitation. Consumer exploitation is taking advantage of the consumers. The term "hoarding" may include the practice of obtaining and holding resources to create artificial scarcity, thus reducing the supply, to increase the price, so that they can be sold to customers for profit.

(b) The black market is the strategy used to by the seller to sell the commodity in higher by creating the artificial scarcity. This is market place which takes place outside government-sanctioned channel.

(c) It is the process of mixing or substituting the identical and undesirable materials in the food items. This will cause heavy loss to the consumers and also leads to many diseases while consuming undesirable commodities. For example Mixing of bricks powder in chili powder, because both are identical and the consumer cannot differentiate it.