The answer is D. This means that is you have a determined amount of force (in newtons) being applied on an object of known mass (in kilograms), then to determine the acceleration of the object, divide the force by the mass (or multiplying the force with the inverse of the mass of the object). This behavior of objects is stipulated in Newtons/ second law. Increasing the force increases the acceleration while increasing the mass decreases the acceleration of the object. Acceleration is a vector quantity meaning it has magnitude and direction.
Proteins are made of hundreds and thousands of polymers called Amino Acid which are attached with each other in long chains. There are 20 different types of amino acids that make up a protein