Solution

The correct answer is option 4.

Key Points

1. Heuristic search is a search technique that seeks to solve a problem by iteratively enhancing the solution using a heuristic function or a cost analysis. Heuristic search is two types.  Direct Heuristic Search Techniques in AI( Breadth-First Search (BFS) and Depth First Search (DFS).) and Weak Heuristic Search Techniques in AI (Best-First Search, A* Search, etc)
2. Every AI program has to do the process of searching for the solution steps that are not explicit in nature.
3. knowledge plays a vital role in intelligence as well as creating artificial intelligence. 

∴ Hence the incorrect statement is It works on or implements a repetition mechanism.