Based on the diagram, how do planarians benefit from sexual reproduction? (see pic)

This question have choices.
A) Sexual reproduction is simpler and requires less energy than asexual reproduction. 
B) Sexual reproduction produces genetic variation in offspring. 
C) Sexual reproduction does not benefit planarians since asexual reproduction is an alternative. 
D) Sexual reproduction creates genetically identical offspring.

Planarians benefit from sexual reproduction because  B.) sexual reproduction produces genetic variation in offspring.

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.