What characterizes a syntax error in programming?

A syntax error in programming occurs when the code violates the rules governing the structure or grammar of the programming language. This means that the code is not written in a way that the compiler or interpreter can understand and process. Common examples of syntax errors include missing punctuation, incorrect keyword usage, or a mismatch in parentheses.

When a syntax error is present, the program will not compile or run until the error is corrected, making it essential to adhere to the language's conventions and syntax rules. This is why option B is the correct characterization of a syntax error—it focuses on how the mistake arises from not following the established conventions and symbols of the programming language, which prevents the code from being executed properly.

The other options do not accurately describe syntax errors or highlight key aspects necessary for understanding this type of error. For instance, mistakes made during run-time execution refer to errors that occur while the program is running, while an error that goes undetected by the compiler would generally pertain to logical or runtime errors, not syntax errors. Additionally, a syntax error typically prevents any functionality from being realized until it is corrected, which contradicts the idea that it has no effect on the program's functionality.