What effect occurs due to parallax?

The correct choice is based on the concept of parallax, which is an apparent shift in the position of an object when viewed from different angles or locations. This phenomenon is commonly observed in astronomy and surveying, where the position of a celestial body or a nearby object appears to change relative to a more distant background due to the observer's change in vantage point.

When a surveyor or astronomer moves from one location to another, the angle at which they observe an object changes, leading to a different apparent position of that object. This is crucial for accurate measurements in surveying, as it helps to determine the distance to objects and their true positions on the landscape.

In contrast, the other options do not accurately reflect the definition of parallax. The change in distance to a celestial object is not directly caused by parallax, but rather by the object's actual movement or the observer's position relative to it. Alteration in solar time relates to the changing position of the sun in the sky over a day, not to the apparent shift in position of objects due to parallax. Similarly, a change in light brightness pertains to variations in the intensity of light emitted or reflected by an object, rather than its apparent position as influenced by the observer’s angle. Thus,