Final answer:
The correct alignment in an optical system for the question given is to align the base of the specimen with the apex of the spherically-seated block, based on the principles of optics and the behavior of light in optical systems.
Step-by-step explanation:
The question appears to be related to the principles of optics, specifically the alignment of images in optical systems such as mirrors or lenses. The correct answer here is: Align the base of the specimen with the apex of the spherically-seated block. This is because by tracing the principal rays from the base of the object, we acknowledge that the base of the image will be located on the optical axis, which is a reference line used to determine the path of light through the system. Given the symmetry of optical systems and the way images are formed by spherical mirrors or lenses, the image of the base is vertically aligned with the image of the tip such that they have a common vertical orientation.