All of the following are accurate statements about pretests and posttests except:
A. In order to be an experiment, there must be a posttest.
B. In order to be an experiment, there must be a pretest.
C. Some experiments have multiple posttests and pretests.
D. Pretests provide a direct measure of change over time.

Pretests provide a direct measure of change over time.

Explanation:

Pretest and post test are part of experimental design.

Experiments design are framework formed to plan about the experiment. so that steps and observation of experiment can be controlled and inference and can be most accurately deduced.

While there are many experimental design, the problem here is concerned about pretest and post test control group design.

In pretest test data about outcome is noted before any experiment is observed.

In post test data of outcome is noted after the experiment.

Almost every experiment include pretest and post methodology of experimental design to gauge differences in result and determine accurate behavior of experiment under study.

Hence, based on this Pretests provide a direct measure of change over time. is wrong option as the time is not an important fact here.

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.

can you explain it better