سوال ۲۵ کنکور ارشد ریاضی ۱۴۰۵

In which position marked by [1], [2], [3] and [4], can the following sentence best be inserted in the passage?

Its existence is either assumed, as in the case of the point and the line, or demonstrated through the geometric construction of the defined object.

Relevant passage context (definitions paragraph):

"A definition was understood to be a proposition indicating what a given thing is. Thus, for instance, Euclid defined parallels as two straight lines which are located on the same plane, and which when extended to infinity in both directions do not meet in either direction. We will simply point out here that a definition in no way proves the existence of the defined object. [2] Thus, in proposition XXI of Book I of the Elements, Euclid proves that parallels exist by demonstrating that one may draw through a point situated outside a straight line another straight line that does not cut the first."