Which of the following is true about shifts in scientific knowledge?
a.
major shifts in scientific views occur daily based on new research, and old scientific principles are frequently discarded without proof.
b.
shifts or modifications in scientific views never occur because scientific ideas can never be questioned or changed.
c.
major shifts in scientific views very rarely occur, but minor modifications of prior knowledge are continually made based on new research.
d.
minor modifications to prior knowledge very rarely occur, but major shifts in scientific views are made very frequently based on existing research.