it's a two part question, please help.

Researchers are interested in the relationship between family history of Alzheimer's disease and early onset of senile dementia. The study design team decides that they will recruit patients from their database based on their performance on the Mini-Mental State Examination (MMSE). Those that meet the threshold for determination of the outcome will be actively recruited, and frequency matched to two controls with normal memory performance on the MMSE. Exposure history based on a family history background check will be recorded. The following table represents a hypothetical result from the experiment. Family History Present Dementia (MMSE 24) Total No Family History Present Total 450 341 499 682 1023 A) What kind of study is being conducted? B) Calculate the appropriate risk measure to determine the difference in risk for early onset of senile dementia based on exposure status. a. Cross-sectional or naturalistic b. OR=2.00 a. Cohort C b. OR=0.025 a. Case-control study C b. OR=1.07 im (Ctri)