Abdul has volunteered to participate in an experiment evaluating the effectiveness of aspirin. Neither he nor the experimenters know whether the pills he takes during the experiment contain aspirin or are merely placebos. The investigators are apparently making use of .

B). The double blind procedure.

Explanation:

'The double blind procedure' is demonstrated as the procedure or method of experiment in which both the experimenter as well as the subjects or participants of the experiment are 'blind to' or 'unaware' of the crucial/significant aspects like hypothesis of the experiment

As per the question, the 'double blind procedure' is being employed by the investigators as neither the subject of the experiment nor the experimenter know about the 'experiment containing aspirin or mere placebos' which would help in producing the objective and unbiased deductions. Thus, option B is the correct answer.

according to hess's theory, when the magma cooled, it would expand and push the tectonic plates apart. it would push the north and south america plates to the west and eurasia and africa ones to the east. the atlantic ocean would get wider but the coastlines of the masses would stay the same.

harry hammond hess was a geologist and a united states navy officer in the second world war. he is considered to be one of the founding fathers of the theory of plate tectonics. he is known for his theories on sea floor spreading, stating that the movement of the continents was the result of see floor spreading. the continents are attached to the plates and do not move separately. the plates themselves shift and change shape, carrying the continents along.

which of the following is a subsurface event that takes place during the rock cycle?