According to piaget which normally developing child would most likely have just begun to engage in preoperational thinking?

It seems that you have missed the necessary options for us to answer this question, so I had to search for it. Anyway, here is the answer. So according to Piaget, the one that would most likely  have just begun to engage in pre operational thinking is a 24-month old-child. Hope this answers your question.

Ghana, first of the great medieval trading empires of western africa (fl. 7th–13th century). it was situated between the sahara and the headwaters of the sénégal and niger rivers, in an area that now comprises southeastern mauritania and part of mali.

That is true , instead try to have a sit down talk with them