which one of the choices are right for the first pic?

Explain why it is a bad idea to have the first five subjects learn from a store clerk that the price has increased to $550, the next five learn that the price has increased to $550 from the price tag on the rug, and so on. Instead, the order in which subjects are sent to the store and which scenario they will encounter (type of change and source of information about the change) should be determined randomly. Why? (c) The order of scenario exposure to each subject should be randomly determined because Randomizing the order controls for other confounding variables such as time of day. If the order is not randomized, the first set of subjects may spread the word about price changes before the next set of subjects enters the store. Randomizing the order of the price change and source of price change information eliminates the bias of the researcher. The order of price changes needs to be randomized so that the store does not incur the impacts of the same price change all at one time. A marketing researcher wishes to study what factors affect the perceived fairness of a change in the price of an item from its advertised price. In particular, does the type of change in price (an increase or decrease) and the source of the information about the change (from a store clerk or from the price tag on the item) affect the perceived fairness? In an experiment, 20 subjects interested in purchasing a new rug are recruited. They are told that the price of a rug in a certain store was advertised at $500. Subjects are sent, one at a time, to the store, where they learn that the price has changed. Five subjects are told by a store clerk that the price has increased to $550. Five subjects learn that the price has increased to $500 from the price tag on the rug. Five subjects are told by a store clerk that the price has decreased to $450. Five subjects learn that the price has decreased to $450 from the price tag on the rug. After learning about the change in price, each subject is asked to rate the fairness of the change on a 10-point scale with 1 "very unfair" to 10 = "very fair