While Looking at Some Seawater Through Your Microscope,you Spot the Egg

While looking at some seawater through your microscope,you spot the egg of an unknown animal.Which of the following tests could you not use to determine whether the developing organism is a protostome or a deuterostome?

A) See whether the ectoderm forms the mature animal's skin/exoskeleton or nervous system.
B) See whether the animal exhibits spiral cleavage or radial cleavage during early development.
C) See whether the coelom is formed from a split in the mesoderm or from mesodermal pockets pinched off the gut.
D) See whether the pore formed during gastrulation becomes the mature animal's mouth or its anus.