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

Multiple Choice

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.
-When diatoms die, their shells fall to the floor of the ocean or lake that they inhabit and form sediments called diatomaceous earth (DE) .
Diatoms can be identified by their shells. Different species of diatoms prefer different water temperatures. What information can be gained if scientists take samples of long-existing DE and identify the diatom species that created it?

A) Scientists can decipher evolutionary lineages between diatom species.
B) Scientists can predict future trends in greenhouse gas emissions.
C) Scientists can learn about past climates.
D) Scientists can better understand how wind currents affect water temperature.