When some subjects exit the experiment before it is completed and this affects the results of the study, this is an example of a(n):.

the answer is d.index

d - failures.

the only attempted british colony in north america before 1600 was roanoke, virginia, which was a total failure. england claimed several areas, including newfoundland, but made no sustainable attempts to colonize them before 1600.

answer; degradation ceremony;