"The mass of Substance C is five times the mass of Substance B", the given statement is correct.
Answer: Option D
<u>Explanation:</u>
As Jessie added 16 gm. of Substance A to 4 gm. of Substance B Obtained certain amount of Substance C which can be calculated as follows:
amount of Substance C = Substance A + Substance B = 16 + 4 = 20 gm
Therefore, 20 gram of Substance C was obtained. Here, fourth statement is correct which says the mass of Substance C ifs five times the mass of Substance B to justify this, see the below:

Systematic Observation is a method used to understand how a particular activity or task works. The researcher observes the stages of a process, the tools used, the difficulties that appear, the conversations and the results of the work.
From this method the conclusion is a consequence of the whole process so it is acquired, the whole process of analysis will lead to the conclusion.
Answer:
D, breaking up different unionized labor strikes and vetoing the Taft-Hartley Act, for PLATO users
Explanation:
got 100% on the test
C is incorrect, because MacArthur was removed in the second term, not the first like the question is asking :)
Answer:
e. psychoanalytic
Explanation:
Psychoanalytic perspective: The psychoanalytic perspective was proposed by the famous psychologist named Sigmund Freud during the late 19th century. It mainly focuses on treating mental illness or disorders by analyzing the association or connection between the unconscious and conscious mind.
The psychoanalytic perspective defines the importance and utility of the unconscious mind. It states that an individual's behavior in the outcome of the past experiences which is present in the unconscious mind to which an individual is unaware of.
In the question above, the therapist's suggestion most directly reflects a psychoanalytic perspective.