To find out whether people's attitudes regarding an issue vary with their ages, karen distributes the same survey to groups of people in their 20s, 30s, 40s, and 50s. what kind of research is karen conducting? choose the correct answer from the following choices, and then select the submit answer button. cross-sequential research

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