B. Soil Contamination
All the other answers are talking about clean and pure things while this answer is the only negative one. So B is your answer.
.75. 75% A because is is a dominant gene. a is 25% because it is recessive, and is mostly overcome by a dominant gene.
Answer:
spores
Explanation:
plant body grows and eventually produce spores through meiosis.These spores divide mitotically to produce haploid (having a single set of chromosomes)