Which characters may be used as the second character of an identifier, but not s the first character of an identifier?

In Java, identifiers are names given to variables, classes, methods, etc. According to the Java naming conventions, the first character of an identifier must be a letter (a-z, A-Z), underscore (_), or a dollar sign ($). Subsequent characters can be letters, digits (0-9), underscores, or dollar signs.

However, there are certain restrictions on using digits as the first character of an identifier. Digits (0-9) are not allowed as the first character of an identifier, but they can be used as the second or subsequent characters.

So, to answer your question, the correct statement is: Digits (0-9) may be used as the second character of an identifier, but not as the first character of an identifier in Java.