Answer:
There is no bar graph attached to this question, however, the question can be answered based on the information given in the question.
The answer is A) average level of happiness
Explanation:
In an experiment, the dependent variable is the variable which is measured by the experimenter. It is the variable that responds to changes made to another variable called independent variable.
In the case of this question, it can be determined, even without the bar graph, that the experiment entails how candy allowance affects a child's happiness. Hence, the candy allowance is changed to influence or cause a response in the child's happiness, which is then measured. Therefore, the AVERAGE LEVEL OF HAPPINESS is the dependent variable.
To minimize the sharp pH shift that occurs when a strong acid is added to a solution, IT IS PRACTICAL TO ADD A WEAK BASE.
When a strong acid is added to a solution, it usually brings about a sharp change in the pH of the concerned solution. To avoid this, one can add a weak base to the solution first. The weak base will serves as a buffer for the strong acid and prevents the solution from experiencing sharp pH variations.
The correct answer is C: the alkaline earth metals!