At the time darwin voyaged on hms beagle, the popularly accepted theory in western culture that explained the origin of earth's plants and animals held that the various species
a) arose continually from non-living materials by spontaneous generation.
b) had been created by divine intervention a few thousand years before.
c) had evolved from now-extinct organisms.
d) arose from a single species that had survived the biblical flood.
e) are all related to one another.

b) had been created by divine intervention a few thousand years before.

Explanation:

In Darwin’s time, most people assumed that all species were brought into being at the same period or age and it was the usual believe. Therefore, Darwin’s ideas which he got from his voyage brought new understanding to biology.

The Voyage of the Beagle

In 1831, Darwin (22 years old) journeyed for a scientific exposition on the HMS Beagle ship. He observed and collected specimens of plants, animals, rocks, and fossils wherever the expedition was ashore. The Figure attached showed his voyage journey. 

Darwin’s Observations

His observations helped him form his theory of evolution. Lets consider:

The great diversity of life.l which was seen in his visit to tropical rainforests and other new habitats where he observed many plants and animals not known to man.

His idea that living things—like Earth’s surface—change over time was from him digging up fossils of gigantic extinct mammals, e.g. the ground sloth proving that organisms differed from their past forms.

evidence and logical support is essential for a scientist to do in order to maintain credibility. this is because no one can believe without any logic and without any evidence.hence a scientist can maintain credibility by proving himself and by answering logically so experiments prove very beneficial. logical hypothesis give conclusion which is acceptable. therefore, there are two main factors to maintain credibility by a scientist is evidence and logical support.