Which instructor took part in changing and improving the end to the original 'Paranormal Activity' film after seeing the potential in the low budget film?

Explanation

With a budget of only 15,000 dollars, the film 'Paranormal Activity' became a huge success worldwide. The film was taped in the main character's living room and is about a phantom that haunts the residents. The director Steven Spielberg was so impressed by this low-budget film that he chose to push it in the right direction by suggesting a different ending. This also created a lot of press, which helped the film become a huge commercial success.