A person holds a block against a vertical wall with some force, F. Which of the following is the correct analysis of the friction force between the block and the wall:

BLUE: Friction force = (weight of block) times (the coefficient of static friction).

PINK: Friction force = (component of F perpendicular to the wall) times (the coefficient of static friction)

YELLOW: There is no friction, because gravity is parallel to the wall.

GREEN: You need more information to proceed.