During the development of a new drug, which would be included in the study by the researcher to prevent any bias or unrealistic expectations of the new drug's usefulness?
a. a placebo
b. fda approval
c. informal consent
d. efficacy information

Option-A

Explanation:

In the given question, since the examiner has mentioned the time that the factor the researcher should include during the development of a new drug is "the placebo". A placebo is used during the experiment as control by and its effect depend on the expectations of the patient since the placebo does not contain the active drugs.

The FDA approval, informed consent and the information are not used until the study is going on.

Thus, Option-A is the correct answer.

estuaries are the partially enclosed coastal bodies of brackish water formed at the mouth of sea where river meets an ocean. it is a transition zone between river and sea water so estuaries are influenced to both marine environment such as tides, waves and to riverine such as flow of fresh water and sediments. the mixing of sea and fresh water provide high level of nutrients, making estuaries a high product habitats.

many estuaries suffers degradation from a variety of human activities like erosion from deforestation, overgrazing, overfishing, drainage and eutrophication.

so from the above statement answers will be

1. false as estuaries are formed due to both brackish and freshwater.

2.true, due to high productivity estuaries are breeding ground for many marine species.

3. direct and indirect activities of man that contribute to pollution and deposition of sediments.