Explanation:

- Section 12 of the Code of Civil Procedure deals with "Bar to further suit." It provides that if a plaintiff is precluded by rules from instituting a further suit in respect of any particular cause of action, he cannot do so.

- Section 11 deals with Res Judicata, i.e., when a matter has already been judged, it cannot be litigated again.

- Section 13 relates to When foreign judgments are not conclusive.

- Section 16 relates to suits to be instituted where subject matter is situated (like immovable property).

Correct Answer: Option 4 - Section 12.