Answer is False.
Any investigation normally begin with an observation. Something that catches the attention. A logical problem-solving approach used by scientists is called the scientific method.
Asking question is the step of a scientific method after observation is made. Then comes hypothesis. A hypothesis is prospective answer to the question which is somehow going to be tested.
Answer:
The answer is antigens
b. cold and dry air
c. warm and humid air
d. warm and dry air