In what way can UV light assist in document examination?

Ultraviolet (UV) light is an essential tool in document examination, as it can reveal features that are otherwise invisible under normal lighting conditions. When applied to documents, UV light can help detect alterations made to the document. This is possible because some inks, particularly those that are altered or added after the original printing, may fluoresce differently under UV light compared to the surrounding material. For instance, a change in ink or the addition of new text may produce distinct patterns or colors that are not visible in normal light, thus helping forensic experts identify forgeries or tampering.

The other choices reflect useful applications of UV light but do not align with the capabilities most relevant to examining alterations. Watermarks can indeed be visible under UV light, but this specific ability does not directly indicate alterations or violations. Similarly, while UV light can enhance the appearance of some inks, not all inks will respond uniformly, and enhancement alone does not provide information on alterations. The original alignment of the paper is typically not determined through UV examination, as this would involve characteristics unrelated to the properties of the inks or the presence of alterations. Therefore, the most pertinent use of UV light in this context is its ability to uncover alterations in a document's content.