I think it is D. The National Institutes of Health found it effective in reducing pain and other symptoms, but it is not clear how it works.
Answer:
I) Sexual reproduction
II) Mutation
Explanation:
Variations refer to the difference observed within organisms of the same species. Variation are introduced into a population by:
- new genetic combinations that occur during sexual reproduction (i.e during meiosis)
- mutations, spontaneous changes that occur in genes and chromosomes.
