Question 7 (2 points) Which statement best completes the sentence below:

Skin, part of the integumentary system, is your body's -

A. organ that increases metabolism.

B. location for white blood cell production.

C. first line of defense against infection.

D. only way to protect from viruses.

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.