According to newton's third law, if one object exerts a force on a second object, the second object exerts a force on the first object that is:

equal in magnitude and opposite in direction

equal in magnitutde and in the same direction

different in magnitude compared to the original force

the same direction as the original force

Equal in magnitude and opposite in direction.

answer is: nuclear fusion produces elements that are heavier than helium.

nuclei combine to form a heavier nucleus, releasing energy.  

for example, fusion of hydrogen atoms at the sun.  

this fusion nuclear reaction is in the inner core of the sun and hydrogen (atomic number 1) is conveted into helium (atomic number 2).  

the inner core is the central region of the sun and all solar energy is produced in the core by nuclear fusion.