Given: Which two code fragments are valid?

This fragment is invalid because it contains a syntax error, such as a missing semicolon, incorrect keyword usage, or an unclosed block, preventing compilation.

This fragment is valid because it adheres to the language's syntax rules for declarations, expressions, or control flow, making it compilable and executable without errors. For example, it could represent a correctly formed variable assignment or method call.

This fragment is invalid due to a syntax or semantic error, such as an undeclared variable, a type mismatch, or an improperly formed statement, which would cause a compiler error.

This fragment is valid as it follows all required grammatical and semantic rules of the programming language, ensuring its proper interpretation and execution. It demonstrates correct usage of keywords, operators, and statement structures.

This fragment is invalid because it violates specific language rules, such as incorrect operator usage or an improperly structured statement, making it impossible for the compiler to process.