Apache Spark Certification Practice Test

The command to check the version of the Java compiler in Cygwin is 'javac -version'. This command directly invokes the Java compiler (javac) and requests the version information. Unlike the command for checking the Java runtime version, which is 'java -version', the 'javac' command is specifically associated with compiling Java programs and hence provides the relevant version of the Java compiler itself.

Other options present commands or formats that are not recognized for this specific purpose within Cygwin or any typical terminal environment. For instance, 'java -version' relates to the Java runtime and not the compiler. 'javac -check' is not a valid command in this context, and 'version java' does not conform to standard command syntax for checking version information in Unix-like systems, including Cygwin.