If subjects are led to believe that a person involved in the study is another subject, experimenter, or bystander, when he or she is actually part of the experimental manipulation, this would be an example of a/an

Confederate.

Explanation:

This is explained to be a test of conformity towards or in accordance with human behaviour and it is further explained to be a scenario when someone in secretly seen to be involved directly or indirectly in the said experiment. In many cases, tgere are also groups tagged to be control grouos where also this confedrate presence is not noticed or negligible according to research; thereby taking a toll on the researchers to determine if participants naturally behave that way.

the correct answer is the following is a list of inventions made in the medieval islamic world, especially during the "islamic golden age" (8th to 13th centuries),[1][2] as well as the late medieval period, especially in the emirate of granada and the ottoman empire.

science and technology in the islamic world adopted and preserved knowledge and technologies from contemporary and earlier civilizations, including persia, india, china, and greece-roman antiquity, while making a number of improvements and innovations.

it should be d or b but i'm sure it's d