Brian, Chris, and Damien took a math test that had 20 questions. The number of questions Brian got right is 14 more than the number of questions Chris got right. Damien correctly answered 2 less than the number of questions Chris answered correctly. If Brian and Damien have the same score, which statement is true? A.
Brian and Damien both answered 2 fewer questions correctly than Chris did.
B.
Brian and Damien both answered 4 more questions correctly than Chris did.
C.
Brian and Damien both answered 2 more questions correctly than Chris did.
D.
Brian and Damien both answered 4 fewer questions correctly than Chris did.

Aresearch study is studying the effects of a new drug for osteoporosis alzheimer's disease (ad) for women above the age of 65 years. a group of individuals with osteoporosis is randomized into two groups. one group is treated conventionally, and the second group is treated with the new medication. assessments are made at 3, 6, 12, 36, and 48 months. the conventionally treated group is assessed for ad using a serum blood test, and the treatment group is assessed for ad using a pet radiotracer that binds to beta-amyloid plaques. in comparing these 2 trial arms, the authors of the study may encounter which type of bias? a. selection bias on the risk of developing b. measurement bias c. confounding bias d. recall bias e. lead-time bias