Answer:
When a writer writes a psychological suspense, the type of activity the author has to develop for the plot is:
mental
Step-by-step explanation:
Psychological suspense are stories that spin surrounding mental sphere plots that make the argumental twists be originated by mental games or in other words. Psychological battles to achieve different objectives. We will always find, that psychological suspense has very smart characters that will find success in their movements with very low physical effort, because they will use the power of their intelligence to influence someone else to fight for them, or just because they are smart enough to avoid fighting at the lowest level possible. An example of this is the promised neverland story in which characters are children that fight against monsters with their strategical thinking to overcome them.