The fate of three U.S. citizens who have disappeared or been imprisoned in Iran was discussed during Friday's historic conversation between the two nations' presidents, a senior U.S. administration official said. 

U.S. President Barack Obama, during his phone call with Iranian President Hassan Rouhani, "noted our concern about three American citizens who have been held within Iran -- Robert Levinson, Saeed Abedini, and Amir Hekmati -- and noted our interest in seeing those Americans reunited with their families," the official said. 

Two of the Americans have been tried and convicted in Iranian courts, and the whereabouts of another have been unknown for more than six years. 

Here are the most recent developments in the stories of the detained U.S. citizens: 

Bob LevinsonThe family of Levinson, a retired FBI agent, has been anxiously waiting for news, any news, about his fate since he vanished during a business trip to Iran in March 2007. 

When Rouhani, Iran's new president, arrived in New York, Levinson's wife and children were watching closely for a sign that efforts to find Levinson might move forward. 

During an exclusive interview with CNN's Christiane Amanpour, Rouhani offered little when asked what he can tell Levinson's family. 

"We don't know where he is, who he is," Rouhani said. "He is an American who has disappeared. We have no news of him." 

Yet, like former President Mahmoud Ahmadinejad, Rouhani spoke of cooperation. 

"We are willing to help, and all the intelligence services in the region can come together to gather information about him to find his whereabouts," Rouhani told Amanpour.  QUESTIONS:

Q1:
1. Who currently serves as President of Iran?
2. What is the name of Iran's acting President?
3. Who fills the role of Iran's President?
Q2:
1. Who did Hassan Rouhani hold court with?
2. Who had a conversation with Hassan Rouhani?
3. Who spoke with the President of Iran?
Q3:
1. What did Hassan Rouhani and Barack Obama talk about?
2. What did the Iranian and American Presidents discuss?
3. What was the topic at hand when Hassan Rouhani and Barack Obama spoke?
Q4:
1. Have any of the Americans in Iran been convicted?
2. Have there been trials and convictions for some of the Americans in Iran?
3. Has Iran upheld convictions of some Americans being held there?
Q5:
1. How many Americans in Iran have been convicted of something?
2. How many court convictions are there against Americans in Iran?
3. How many of the Americans being held in Iran have been convicted of a crime?
Q6:
1. What is the location of the American who has not been convicted of anything in Iran?
2. Where is the American in Iran with no conviction against them?
3. WHere is the non-convicted American being held in Iran?
Q7:
1. When did Bob Levinson go missing?
2. When did Bob Levinson's disappearance occur?
3. When was Bob Levinson declared missing?
Q8:
1. What was Bob Levinson's occupation?
2. How was Bob Levinson employed?
3. What did Bob Levinson do for a living?
Q9:
1. Is Bob Levinson still working for the FBI?
2. Is Bob Levinson presently employed by the FBI?
3. Does Bob Levinson continue to work as an FBI agent?
Q10:
1. Does Bob Levinson have a family?
2. Is there a family in Bob Levinson's life?
3. Has Bob Levinson left a family behind?
Q11:
1. Who is in Bob Levinson's family?
2. What family members has Bob Levinson left behind?
3. What members of his family are missing Bob Levinson?
