Newton's law of universal gravitation can be applied to only to very massive objects
to any two objects with mass
only to objects near Earth's surface
only objects in outer space

To any two objects with mass because a pencil and a paper can have gravitational force but they won’t be attracted to each other due to earths stronger gravitational pull another example would be meteorites which also have gravitational pull but not enough to be attracted each other unless there’s nothing except them around

Letter a, because when there are unlike charges they will always attract to each other.