The correct answer for the question is B. Fossil.
Fossils are remnants, traces of animals or plants, from the past ages that have been preserved. Fossils may be classified as cast and mold fossil, insect preserved in amber, petrified wood, compression fossil of a fern and pyritized ammonite.
Answer: It is because it makes it more efficient to study organisms.
Explanation: Biologist classify organisms by considering similarities between them. The organisms which have closely related characteristics are placed in a separate domains by biologists. Domains are further divided into 6 Kingdoms. According to modern classification system, domain is largest unit of biological classification.
Gravity Probe B showed this to be correct, in 1905 Einstein determined that all laws of physics are the same for all non accelerating observers <span />