Final answer:
During mass extinction events, including those associated with Snowball Earth, more than 50% of species have typically gone extinct. This is based on patterns observed in the fossil record across multiple mass extinction events. thus, the correct option is B).
Step-by-step explanation:
The question pertains to the percentage of species that went extinct during the Snowball Earth episode(s). During the mass extinction events in Earth's history, it is noted that five mass extinctions resulted in the loss of more than 50 percent of extant species.
For example, during the end-Permian mass extinction, about 250 million years ago, 96 per cent of all species became extinct. Similarly, approximately 85 percent of marine species went extinct during the Ordovician-Silurian extinction which was also associated with significant climatic changes due to glaciation and warming.
The Snowball Earth hypothesis refers to periods during which Earth's surface was nearly or entirely frozen. These episodes would have had dramatic effects on biodiversity.
Although the exact percentages of species extinction during the Snowball Earth episodes are not provided in the information available, the examples of past mass extinctions, where typically more than 50% of species were lost, can be indicative of the severity of these periods. Therefore, the most likely answer, in general, is that more than 50% of species went extinct during these severe climatic episodes.