Which of the following is true about a spinal reflex

 A. It is controlled by the brain. B. It is an involuntary response to a stimulus. C. It is a voluntary contraction of muscles. D. It increases blood flow to muscles.

The answer is atmosphere. there are four spheres of the earth: 1. geosphere (from greek word 'geo' = ground), 2. hydrosphere (from greek word 'hydro' = water), 3. biosphere (from greek word 'bio' = life), and 4. atmosphere (from greek word 'atmo' = air). a magnetosphere is a region of space around astronomical objects controlled by the magnetic field of that object. through the process of elimination, since lightning is present in the air, it can be found in the atmosphere.