This illustration shows an elevator accelerating upward with an astute observer inside.$$A photon in a beam of light entering the a hole on the upper right proceeds from right t left. Rather than take a straight path parallel to the floor of the elevator, a moment after entering the photon has moved across and is lower, relative to the floor, than it was when it entered. Indeed, tracing the path across, the observer would perceive the photon is travelling downward in his frame of reference.

Einstein's "Principle of Equivalence" is that the effect of gravity is indistinguishable from the the effect of acceleration.$$From the choices offered, pick the the conclusion we must draw from this hypothetical "thought experiment" if gravity and acceleration have the same observable consequences.

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The path of light is altered by gravity and light follows a curved path near massive objects, as if attracted to the object, although it has no mass

The path of light is not altered by gravity

That light has mass

That stars appearing near the Sun during a solar eclipse will be at the same apparent position they would be if the Sun were not there