The answer is field investigation.
<span>A field investigation includes observation of
free-living animals in their natural habitat without affecting them, their
behavior, or their habitat. So, observation of tigers' activity in their native habitat is an example of the field investigation. The investigator would simply observe their behavior, not affecting the tigers in any way.</span>
A independent variable is a variable which the experimenter can control and by changing the independent variable the experimenter observes or records the value of dependent variable.
so i see if you are asking independent than the answer is A.
if you are asking dependent variable than the answer may be B because manipulated by changes to the independent variable would be the best answer.
They are cold blooded
They respire both by Skin and lungs.
They lay eggs in water ; they have a 3 chambered heart.
Atoms are the smallest building blocks of elements having the same chemical and physical properties of that specific element. Atoms combine together with the help of electrons, to form a little more complex entity like the molecules, crystals, liquids etc. Some molecules combine together to form a more complex entity like the DNA which is the most complex molecule. The whole universe is made out of these simple building blocks, including the human body.
Prostate Gland is a<span> single, doughnut-shaped gland about the size of a chestnut or golf ball.</span>
