Answer:
The answer is most likely A. Definite proportions
Explanation:
The Law of Definite proportions states that a given chemical compound always contains its component elements in fixed ratio (by mass) and does not depend on its source and method of preparation.
By definition a cylinder is a solid geometric figure with straight parallel sides and a circular or oval cross-section. A good example of a cylinder would be a soda can.
Independent variable: the student chooses to miss class.
dependent variable: in result of the student missing class his grade goes down.
hyposthesis: if the student misses class multiple times, then his grades will go down.