ANS: a), but you may not have to extend her H-4 until Nov 2007.
2. When should I request for the new expiration date, 3 years from now or other date?
ANS: same duration as your H-1
3.Is my daughter an applicant for an immigrant visa?
ANS: You already did as you filed I-485 for her
4. Has an immigrant petition ever been filed for my daughter?
ANS: Yes, as you filed I-485 for her