A.1eo.roar = () => 9 (console.log('They\'re pretty good1'); 1;

B.Object.assign, assign( 1eo, trigger);

C.1eo.prototype.roar = ( ) => ( console.log (They\'re pretty good1'); );

D.Object,assign(1eo, tony) ;

A.Add event,stopPropagation (); to window,onLoad event hadler.

B.Add event,stopPropagation (); to printMessage function.

C.Add event,stopPropagation (); to window.onLoad event hadler.

D.Add event,stopPropagation (); to printMessage function.

A.'hidden'; 'visible'

B.'Block' ; 'none'

C.none' ; 'block '

D.'Visible' ; hidden'

A.Option B

B.Option C

C.Option D

D.Option A

A.An error

B.Undefined

C.'new york'

D.'New York