Correct answer is option B, C, D.
A. 'use strict' has an effect only on line 05.

Incorrect: "use strict" affects the entire scope (function or file) from the point where it is declared until the end of that scope. It does not limit its effect to a single line.
B. z is equal to 3.14.

Depends on the Context: Without the actual code, this cannot be definitively assessed. However, if strict mode is in effect and the code tries to assign to an undeclared variable z, it would throw an error in strict mode.
C. 'use strict' has an effect between line 04 and the end of the file.

Correct: "use strict" affects all code from the line it is declared until the end of the file or function scope. This is true for a file-wide directive.
D. Line 05 throws an error.

Correct (with Context): If line 05 contains code that is disallowed in strict mode (such as assigning to an undeclared variable or using reserved keywords), then it would indeed throw an error in strict mode. For example, if line 05 tried to assign a value to an undeclared variable, strict mode would throw an error.
E. 'use strict' is hoisted, so it has an effect on all lines.

Incorrect: "use strict" is not hoisted. It only affects the code following it in the scope it is declared. It does not apply to all lines or globally unless it is declared at the top of a file or function....