Question: What president was assassinated in an explosion on August 1981, and was succeeded by a man elected as the new Supreme Leader by the Assembly of Experts on 4 June 1989 at the age of 49?

<P0-S0> Sayyid Ruhollah Mūsavi Khomeini (Persian: سید روح‌الله موسوی خمینی‎ ‎ ] ; 24 September 1902 – 3 June 1989), known in the Western world as Ayatollah Khomeini, was an Iranian Shia Muslim religious leader, philosopher, revolutionary, and politician. <P0-S1>  He was the founder of the Islamic Republic of Iran and the leader of the 1979 Iranian Revolution that saw the overthrow of the 2500 years of Persian monarchy and Mohammad Reza Pahlavi, the last Shah of Iran. <P0-S2>  Following the revolution, Khomeini became the country's Supreme Leader, a position created in the constitution of the Islamic Republic as the highest-ranking political and religious authority of the nation, which he held until his death. <P0-S3>  He was succeeded by Ali Khamenei on 4 June 1989. <SEP> <P1-S0> In August 1981, President Mohammad-Ali Rajai and Prime Minister Mohammad-Javad Bahonar were assassinated in an explosion. <P1-S1>  Ali Khamenei was then elected as the third president of Iran in the Iranian presidential election, October 1981. <P1-S2>  He put forward Ali Akbar Velayati as his prime minister, but the Iranian parliament did not give him the vote of confidence, and he was defeated with a vote of 80 to 74. <P1-S3>  Subsequently, Ali Khamenei, though he had strong disagreements with Mousavi, as a compromise with the left-leaning parliament, agreed to offer him, Mousavi, for the post of premier. <P1-S4>  On 28 October, the parliament approved Mousavi with a vote of 115 to 39. <P1-S5>  Mousavi became the 79th Prime Minister of Iran on 31 October 1981, and remained the prime minister of Iran until 3 August 1989, for eight years. <SEP> <P2-S0> Mohammad-Ali Rajai (Persian: محمدعلی رجائی‎ ‎ ; 15 June 1933 – 30 August 1981) was the second President of Iran from 2 to 30 August 1981 after serving as prime minister under Abolhassan Banisadr. <P2-S1>  He was also minister of foreign affairs from 11 March 1981 to 15 August 1981, while he was prime minister. <P2-S2>  He was assassinated in a bombing on 30 August 1981 along with prime minister Mohammad-Javad Bahonar. <SEP> <P3-S0> Sayyid Ali Hosseini Khamenei (Persian: سید علی حسینی خامنه‌ای‎ ‎ ] ; born 17 July 1939) is a "marja" and the second and current Supreme Leader of Iran. <P3-S1>  Khamenei succeeded the first Supreme Leader, Ruhollah Khomeini, after Khomeini's death, being elected as the new Supreme Leader by the Assembly of Experts on 4 June 1989 at the age of 49. <P3-S2>  His political career began after the Iranian Revolution, when the former President of Iran, Akbar Hashemi Rafsanjani, then a confidant of Khomeini, brought Khamenei into Khomeini's inner circle. <P3-S3>  Later on, the current President of Iran, Hassan Rouhani, then a member of Parliament, arranged for Khamenei to get his first major post in the provisional revolutionary government as deputy defense minister. <P3-S4>  Khamenei then went to serve as the third President of Iran from 1981 to 1989 while becoming a close ally to Khomeini. <P3-S5>  Eventually, after Khomeini had a fall off with then heir-apparent Hussein Ali Montazeri, Rafsanjani claimed that Khomeini had chosen Khamenei as his successor while the Assembly of Experts deliberated to elect the next Supreme Leader. <P3-S6>  Khamenei is head of the servants of Astan Quds Razavi from April 14, 1979.