The gold standard of research designs are: Question 30 options: a) Adequate sample sizes b) Randomized controlled trials c) Free of known bias d) Adequate pilot testing

b) Randomized controlled trials

Explanation:

Randomized controlled trials are usually viewed as the "gold standard of research designs" because they have a great potential of limiting or even eliminating all sorts of bias, and, therefore, provide the highest level of evidence when performing a research.

The answer is b) Randomized controlled trials

B) Randomized Controlled trials

Explanation:

Randomized controlled trial is (RCT) study in which people are allocated at random  to receive one of several clinical interventions.A Randomized Controlled Trial is an experiment or study conducted in such a way that as many sources of bias as possible are removed from the process.

Of all the many ways research can be conducted, the gold standard level of proof where treatments and therapies are concerned is the Randomized Controlled Trial (RCT). ...

the answer to your question is,

d. when a child was born.

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