Where is a divergent boundary most likely to be found?

Ineed to know why d is the correct answer asap

What is thought to have caused the mass extinction at the end of the cretaceous period?

If two parents who's blood types are both b produce a child that has blood type o, what can you say about the parent's genotybes? oa) one is ii ob) one is ibi oc) both are bi od) nothing, this is impossible