Please Use the Following Information to Answer the Question(s) Below

Please use the following information to answer the question(s) below.
Healthy individuals of Paramecium bursaria contain photosynthetic algal endosymbionts of the genus Chlorella. When within their hosts, the algae are referred to as zoochlorellae. In aquaria with light coming from only one side, P. bursaria gathers at the well-lit side, whereas other species of Paramecium gather at the opposite side. The zoochlorellae provide their hosts with glucose and oxygen, and P. bursaria provides its zoochlorellae with protection and motility. P. bursaria can lose its zoochlorellae in two ways: (1) if kept in darkness, the algae will die; and (2) if prey items (mostly bacteria) are absent from its habitat, P. bursaria will digest its zoochlorellae.
-The diatoms' porous shells are hard but often break and result in sharp edges. Crop farmers incorporate DE into their soil to help kill insect pests. When insects encounter DE, sharp shell edges cut through their exoskeletons and then softer, broken down DE absorbs insect body fluids, thereby causing the insects to die due to dehydration. Why might farmers who raise large livestock also use DE in the animals' feed?

A) The sharp shells can damage the tissue of intestinal parasites and eventually kill them.
B) DE helps to slow down the livestocks' digestion of food, thereby increasing nutrient absorption.
C) The porous nature of the shells in the DE helps keep livestock hydrated.
D) DE encourages growth of "healthy" intestinal bacteria.