Explain what is meant by “field” and compare the properties of gravitational, electric, and magnetic forces in terms of particles affected, factors affecting the magnitude, and their relative strengths.

A field is the description of a spatial region, the force exerted on objects by a field is a field force. 
gravitational force field: surrounds every material object, although only objects planet-sized or larger exert significant gravity.
electric force field: surrounds and affect electrical charges
magnetic force field: surround magnets and materials with electricity flowing through them. magnetic fields affect susceptible materials such as iron or other magnets.
hope i helped a little

B. convex since the words are bigger