Which of the following is added to prefs.js,when open a dialog box each time an error occurs?

A) user_pref(“javascript.classic.error_alerts”, true);

B) user_pref(“javascript.classic.error_alerts “, false);

C) user_pref(“javascript.console.open_on_error “, false);

D) user_pref(“javascript.console.open_on_error “, true);