The best answer to the question states above is letter C.<span> A short observation period.
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<span> A scientist's primary concern in a clinical trial is the patient's safety, there fore short observation </span><span>decreases the reliability of results from a clinical trial</span>
Examples of abiotic factors are water, air, soil, sunlight, and minerals.Biotic factors are living or once-living organisms in the ecosystem.
Biotic describes a living component of an ecosystem; for example organisms, such as plants and animals.
Examples Water, light, wind, soil, humidity, minerals, gases.
<u><em>Hope this helps!</em></u>
Energy is stored in the chemical bonds.
Incomplete please thank and mark brainliest