The answer is B about cycle
Answer:
In open systems both matter and energy move into and out of the system. Earth's four spheres are open systems. These four spheres work together to form one large closed system called Earth. The atmosphere is a mixture of gases that surrounds and protects our planet.
Explanation:
electron = negative charge (I remember this one is negative because it is not the other two )
proton = positive charge (aka "P" is for "Positive")
neutron = no charge (aka "N" is for "No charge")
Hope this helps!