Answer:
B) central-route processing
Step-by-step explanation:
Robert has developed a favorable attitude toward a brand of stationery known as Impress because the brand is eco-friendly and promotes sustainability. He has since learned, through his own research, that Impress also engages in fair trade practices. Robert's attitude formation is an example of central-route processing. Central-route processing is a type of processing of information and attitude formation that relies on an individual's ability to carefully and correctly evaluate the arguments in a persuasive message.
Robert is able to evaluate the message and arguments on sustainable environment and hence forms his decision towards favouring the Impress brand because of their eco-friendly practices.