Read the passage carefully and choose the correct answer

Our family members resemble each other because we have the same genetic formation in our DNA, and this formation has been passed from parents to children for many generations. Much like the children humans create, plants pass on their genetic formation in their seeds. The seeds of endangered and imperiled plants are so valuable because there are no other plants in the world with that same genetic formation, and we are at risk of loosing these genetic resources forever. But preserving the genetic diversity of some species can be quite difficult. When researchers and conservationists preserve a plant, one of their goals is to preserve genetic variety. “By preserving the genes of these plants, we preserve the possibility for adaptations in the future,” explains Dr. Christina Walters, a plant physiologist. After collected seeds must be stored for future use, planting or research. Since seeds begin to grow when it is warm and wet, scientists store seeds in places that are cold and dry, which is called a seed bank. But not all seeds survive the drying and freezing treatments, and care must be taken so that they are not harmed during banking. When researchers attempt to store a seed, they examine what is known about the growth habits of the plant, its habitat and geographical distribution, and then classify the seeds by storage needs.

The text is about ____.

• A. 
  generations 
• B. 
  genetic formation
• C. 
  DNA
• D. 
  seed preservation