What is the ethical dilemma associated with randomized controlled studies for suspected causes of disease such as cigarette smoking? a. The prevalence of disease within the study cannot be controlled.
b. The effect of the disease is too detrimental to the health of those involved within the study to allow them to be voluntarily exposed to a suspected cause of disease.
c. Incidence of disease is often determined to be too low to conduct a randomized controlled trial.
d. It is difficult to establish definitive contributory cause even with a high-quality randomized controlled trial.

b. The effect of the disease is too detrimental to the health of those involved within the study to allow them to be voluntarily exposed to a suspected cause of disease.

Explanation:

Randomized controlled studies assess the relationship between cause and effect. There are usually two groups in this study. The first group is the experimental group which is exposed to the treatment or intervention to be assessed while the second group is the control group which is given no treatment or given a placebo.

As it relates to the question, the experimental group is exposed to cigarettes to determine the effect of this exposure. This can have an adverse health effect on the experimental group, hence, this is an ethical dilemma.

the oceanic zone is typically defined as the area of the ocean lying beyond the continental shelf, but operationally is often referred to as beginning where the water depths drop to below 100 meters (328 feet), seaward from the coast to the open ocean.

explanation:

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.