Ques 3 : Which of the following statements are correct. Select the four correct answers.
a. A Java program must have a package statement.
b. A package statement if present must be the first statement of the program (barring any comments).
c. If a Java program defines both a package and import statement, then the import statement must come before the package statement.
d. An empty file is a valid source file.
e. A Java file without any class or interface definitions can also be compiled.
f. If an import statement is present, it must appear before any class or interface definitions.