Newtonian mass

What is mass anyways? When you first learn about mass, it's often introduced as the coefficient that relates the force applied to an object to how the object accelerates. In short, we have the definition of the inertial mass as $m=\frac{\big|\vec{F}\big|}{|\vec{a}|}$ from Newton's second law. Some objects, like electrons and protons, have masses while other objects, like photons, don't. This series of problems will walk you through how one can generate mass for different particles by the Higgs mechanism , which you may have heard of since it has been in the news a lot in the last few years (and is one of the major motivations for the Large Hadron Collider in Europe).

We start with a (hopefully) simple question: Which of the following statements is correct in Newtonian mechanics?