Help, please :) :) both please

Ais a survey that focuses on only a small portion of the population, and the results are generalized for the larger population.

Why are fossils of organism's from the phanerozoic eon much more likely to be found than fossils of organisms from any other eon? a. more organisms present during the phanerozoic eon had soft body parts. b. organisms present during the phanerozoic eon were all microscopic. c. more organisms present during the phanerozoic eon had hard body parts. d. organisms present during the phanerozoic eon are the most ancient life forms.

Which theory suggested that the earth was once a signle supercontient that gradually that broke up into the contients that we know today