Is a reduction in the number of research participants as some drop out of the study over time.
a) attrition
b) experimenter bias
c) single blinding
d) generalizability

The correct answer is letter A

Explanation: Attrition is a reduction in the number of research participants as some drop out of the study over time.

explanation:

with the profits from the european sales, merchants purchased europe's manufactured  goods, including tools and weapons. then the merchants shipped those manufactured  goods, along with the  american  sugar and rum, to west africa where they were bartered for  slaves.