What happens in a nuclear fusion reaction?
a. the nucleus of a larger atom splits into two nuclei of relatively similar size, which then lose their electrons and become anions.
b. the nucleus of a single heavy atom splits into two or more smaller nuclei that have relatively similar mass.
c. the nucleus of a heavy atom combines with the nucleus of a smaller atom, forming an atom with a larger nucleus.
d. the nuclei of two atoms with smaller mass combine to form a single atom with one larger nucleus.

C.

Explanation: During a nuclear fusion reaction, it  gets squeeze together so tightly that four hydrogen nuclei combine to form one helium atom. This is called nuclear fusion. In the process some of the mass of the hydrogen atoms is converted into energy in the form of light. The same process occurs in thermonuclear (fusion) bombs.

enhanced global partnerships and exploration capabilities may advance international preparedness for protecting the earth from catastrophic events such as some asteroid strikes, advancing collaborative research on space weather and protecting spacecraft by developing new means for space debris removal.

explanation:

the universal gravitation equation. since the gravitational force is directly proportional to the mass of both interacting objects, more massive objects will attract each other with a greater gravitational force. if the mass of one of the objects is doubled, then the force of gravity between them is doubled.