Which organism most likely has 10% of the sun's energy available for its use? mouse shrubs snake hawk

Correct B). Shrubs

Most of the plants can only utilize 10% of sunlight intensity, they are not able to utilize all the incoming sunlight energy because of reflection, and also they are not able to convert all the captured energy into biomass. Rest of the energy is used in the growth, reproduction or it is lost as heat.  

Since shrubs are producers, so the correct answer would be option B.