I think the correct answer from the choices listed above is option D. It would be carbon dioxide and water that contributes the most to the mass of a plant. These substances are what the plant needs to carry out photosynthesis with the presence of sunlight. Hope this answers the question.
Karyotyping is <u>a test to examine chromosomes in a sample of cells</u>. This test can help identify genetic problems as the cause of a disorder or disease.