What distinguishes general relativity from special relativity?

General relativity distinguishes itself from special relativity primarily through its application to non-inertial frames, which include scenarios where gravitational forces are present or where acceleration is involved. Special relativity, formulated by Einstein in 1905, is limited to inertial frames—those that are either at rest or moving at constant velocity. It does not account for the effects of gravity or the curvature of spacetime.

In contrast, general relativity, published in 1915, extends the principles of special relativity to include gravitational interactions by describing gravity not as a force but as a curvature of spacetime caused by mass. This allows for the description of phenomena such as gravitational time dilation, the bending of light around massive objects, and the dynamics of objects in a gravitational field, all of which require an understanding of non-inertial frames.

The other choices do not accurately capture the essence of the differentiation between general and special relativity. Although particle physics and quantum mechanics are significant fields of study, they are not the defining aspects of general relativity's distinction. Furthermore, the emphasis on classical mechanics, while relevant to both theories in that they both emerge from it under certain conditions, does not specifically highlight the key distinction in terms of reference frames and gravitational effects