What is wrong with the following code: <a href = "picture.jpg">My dog</a> chews socks?

The assertion that the code is semantically and syntactically correct highlights its accuracy in HTML structure and meaning. The anchor tag is properly opened and closed, and the textual content, "My dog," serves as the clickable link. It's important to understand what "semantically and syntactically correct" implies in this context. The anchor tag fulfills its role by allowing users to navigate to the specified location, which in this case is "picture.jpg". There is no requirement for the href attribute to contain an absolute URL; relative URLs are perfectly valid and often used when linking to resources within the same site or directory.

Therefore, the other choices present misunderstandings about HTML structure. The first choice refers to an 'alt' text, which is actually relevant for image elements, not anchor tags. The second choice incorrectly suggests that text cannot follow a closing anchor tag; however, it is entirely permissible to have text outside of the anchor. The third choice presents a misconception regarding the format of the URL in the href attribute, which can indeed be a relative path as shown here. Overall, the code functions correctly as written and conforms to HTML standards.