D. All of the above are correct
"Apical Meristem Tissue" is the part of the plant among the following choices given in the question where the activity in the plant stem could have caused this. The correct option among all the options that are given in the question is the first option or option "A". I hope that the answer has come to your help.
Answer:
Explanation:
1) Excitation brings about contraction.
2) Contraction leads to an increase in blood pressure.
3) Changes in blood pressure results in the opening and closing of the heart valves.
4) The opening and closing of heart valves then regulates the flow of blood and it's volume.
