To answer this question, you need to understand the meaning of the word "simplistic" and its correct usage.
Option A) In Jim's simplistic view, everyone is either good or bad. - This option is correct because it uses the word "simplistic" correctly to describe Jim's view as overly simplistic or overly simplistic.
Option B) They had a simple plan for rescuing the hostages - This option is correct because it uses the word "simple" to describe the plan, which means it is straightforward and uncomplicated.
Option C) Don't overcomplicate this; we need a simplistic solution. - This option is incorrect because it uses the word "simplistic" incorrectly. The word "simplistic" means overly simplistic or lacking depth and complexity, so it is not suitable for describing a solution that is needed.
Option D) Her message is too simplistic to take seriously. - This option is correct because it uses the word "simplistic" to describe her message as overly simplistic or lacking depth and complexity.
The correct answer is C.