Scientists were interested in determining if the amount of n

Scientists were interested in determining if the amount of nicotine present in tobacco leaves is related to the amount of water received by the plants. In a greenhouse, a total of 120 tobacco plants were selected. During the growing season, 30 plants were randomly assigned to receive the normal amount of water, 30 plants received 75% of the normal amount of water, 30 plants received 50% of the normal amount of water, and 30 plants received 25% of the normal amount of water. At the end of the growing season, one leaf was selected at random from each plant and the amount of nicotine present was recorded for each. Researchers determined that leaves from tobacco plants receiving the normal amount of water during the growing season had more nicotine than leaves from tobacco plants receiving less water.

Choose the statement that restates the conclusions of the study in terms of cause-and-effect conclusion.

A.

The amount of water received by tobacco plants during the growing season does not affect the amount of nicotine in the tobacco leaves.

B.

Normal amounts of water during the growing season produced less nicotine in tobacco leaves than reduced amounts of water.

C.

Reduced amounts of water during the growing season is associated with a decrease in the amount of nicotine.

D.

Normal amounts of water during the growing season produced more nicotine in tobacco leaves than reduced amounts of water.

Solution

D.

Normal amounts of water during the growing season produced more nicotine in tobacco leaves than reduced amounts of water.

is the right answer.

Because when tobacco plants were segregated into 4 groups with different amount of water, test proved that normal amount of water ensured leaves with more nicotine.