First suggested that encoding can be influenced by levels of processing. richard atkinson and richard shiffrin eric kandel and james schwartz fergus craik and robert lockhart martin conway and david rubin

The answer is: Fergus Craik and Robert Lockhart

Both of them realized  that some people often experienced a delayed response after receiving some information that is hart to deal with. This led to the conclusion that to levels of processing exist when we try to encode a certain information. (this can explain why the delay happened)

For example, When a mother heard that her son has died in an accident, that woman would not directly cried the second she heard the news.

She would most likely stunned for a while and unable to  make proper response for other people. This because she experienced a difficult process to pass all the levels of processing needed to receive the information.

answer; (b) ; /stronger bonds between the nations of africa