OK, what options are there?Joseph was the father, but this...

OK, what options are there?

1. Joseph was the father, but this information was denied to protect the integrity of Mary and Joseph and to claim the interpretation of an OT "prophecy"?
2. Mary was not a virgin. This claim was the result of the mistranslation of "maiden|" or "young woman" in the OT.
3. If Joseph was not the father then some other male was.
4. Mary's pregnancy was the result of the act of some Spirit.
5. Mary became pregnant from Joseph's sperm without penetration and hence called a virgin pregnancy?

Which is the most plausible and likely option?