The correct answer is B.
There's no statically significant association between the exposure and the disease. The risk ratio does not follow the normal distribution, even it does not depend on sample size in comparison groups. The natural rr is approximately normally distributed and is used to produce confidence interval which is for the relative risk.
Answer:
4
Explanation:
Carbon has four valence electrons, so it can achieve a full outer energy level by forming four covalent bonds. When it bonds only with hydrogen, it forms compounds called hydrocarbons. Carbon can form single, double, or triple covalent bonds with other carbon atoms.
