Question

For the common ancestor of all the Bilateria, what was the fate of the blastopore?

Answer 1

The right answer here speaing about the blastopore is the last option: It is impossible to tell from the data provided. Indeed the data provided for this fate is not definite and is not possible to know if it was deuterostomy or protostomy

Answer 2

Answer;

It is impossible to tell from the data provided.

Explanation;

Different animals can be categorized as either protostomes and deuterostomes based on certain features of their embryonic developments.

For those categorized as protostome; the features include; mouth from blastopore, spiral,determinate cleavage, and coelom from solid masses of mesoderm

Those categorized as deuterostome have features such as coelom from folds of archenteron, radial, indeterminate cleavage, and anus from blastopore.