What is suggested by the similarity of early embryos of different species of vertebrates?

no evolutionary relationships between the groups
recent common ancestry
similar environments in the past
evolution from a distant common ancestor

I don’t know the answer to this one

the cytokine-activated janus kinase (jak)-signal transducer and activator of transcription (stat) pathway has an important role in the control of immune responses. dysregulation of jak-stat signaling is associated with various immune disorders.