D is the answer. the incas did not have slaves
Answer:
Because they would have been treated the same as men
Answer: This is a "CONTROLLED PLACEBO EXPERIMENT".
Explanation: A controlled placebo experiment is a type of research method that is used to check the effectiveness of a drug in a patient. This is done by selecting a sample group, then randomly divide the two group into a placebo group ( this are the group that will receive the drug treatment ) and the controlled group( these are the group that will receive a coloured mixture that looks like the drug, but does not have any effect). Without the groups knowledge about the real drugs and the coloured mixture, but are followed up and tested.
This is a controlled placebo experiment, because 400 student has been choosed as the sample, and are divided into a placebo group and a controlled group, to check the effectiveness of a drug on their memory.
Wind and solar energy are examples of renewable resources.
