challenge: Who was instructed and prepared by Imām Mustansir and following Imāms for the second period of satr?
  
  A. Imām Taiyab abi al-Qasim
  B. Imām Mustansir
  C. Dā'ĩ al-Mutlaq
  D. Al-Malika al-Sayyida (Hurratul-Malika)
  Answer: 