Tasha is a graduate student studying health and nutrition. A recent study has made claims about the health benefits of dark chocolate. Tasha would like to conduct a similar study to see if she can confirm the findings of the first. She wants to make sure that her study is as close to the original as possible. Which factors of her study can she control? Check all that apply.

Melanocytes and keratinocytes work together in protecting the skin from uv damage when keratinocytes a. provide the melanocyte with a protective shield against abrasion b. maintain the appropriate temperature so the product of the melanocyte will not denature c. maintain the appropriate ph in order for the melanocyte to synthesize melanin granules d. accumulate the melanin granules on their superficial portion, forming a uv-blocking pigment layer