In 1687, explained that gravitational forces hold the solar system together.
a. newton
c. halley
b. copernicus
d. galileo

Newton 

july 5, 1687, isaac newton published work, in which he presented a coherent theory of gravity describes both falling objects on the ground as well as the movement of celestial bodies. english physicist relied on their proposed terms of dynamics and kepler's laws on the distance of the planet from the sun.

C. the delegated powers