Describe the differences between sunspots and solar flares.

Sunspots are dark areas on the surface of the Sun that are cooler than surrounding areas. They appear in groups, vary in size, and cycle in number over an 11-year period. Solar flares are sudden eruptions of energy from a small area of the Sun's surface. They are extremely hot (10 to 20 million degrees Celsius) and extend into the corona. Solar flares occur near sunspots and can disturb radio communications on Earth.

i think it would be b. tissue because an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.

b. the carbon cycle ensures living things have a source of hydrogen