Title: Sergei Sedov
Content:  The son of Leon Trotsky by his second wife, and younger brother of Lev Sedov, Sergei L. Sedov was born in 1908 (age 12). He was an apolitical engineer and scientist whose daughter, Yulia, was born three months after his 1935 exile.
Title: Sergei Sedov
Content:  Sergei L. Sedov (1908 (age 12)1937) was a Soviet engineer and scientist killed in the Great Purge for being the son of Leon Trotsky.
Title: Lev Sedov
Content:  Lev Lvovich Sedov (Лев Львович Седов, also known as Leon Sedov; 24 February 1906 – 16 February 1938) was the first son of the Russian Communist leader Leon Trotsky and his second wife Natalia Sedova. He was born when his father was in prison facing life imprisonment for having participated in the Revolution of 1905.
Title: Sedov (surname)
Content: Anastasia Sedova (born 1995), Russian cross-country skier ; Georgy Sedov, Russian Arctic explorer ; Lev Sedov, son of Leon Trotsky ; Leonid I. Sedov, physicist and first chair of space programme ; Natalia Sedova, the second wife of Leon Trotsky ; Sergei Sedov, another son of Leon Trotsky Sedov (masculine, Седов) or Sedova (feminine, Седова) is a Russian surname. Notable people with the surname include: 
Title: Sergei Sedov
Content:  Despite having taken his mother's surname to avoid political affiliation with his father, in 1935 Sedov "was arrested on trumped-up charges [and] refused to betray [Trotsky]". That year, the Gulag banished Sedov from Moscow to the Siberian city of Krasnoyarsk. Sedov died in 1937, though accounts differ the specifics: some records claim he was killed in a prison uprising, others allege he was shot in Krasnoyarsk after being accused of a poisoning plot, while The New York Times in 1988 asserted that he was returned to Moscow and shot for Trotsky's allegedly plotting to kill Joseph Stalin. After Sedov's daughter Yulia Akselrod petitioned Soviet President Mikhail Gorbachev, Sedov was rehabilitated in late 1988 by the Supreme Court of the Soviet Union.
Title: Leonid Sedov
Content:  Leonid Ivanovich Sedov (Леонид Иванович Седов; 14 November 1907 – 5 September 1999) was a leading Soviet expert on hydro- and aerodynamics and applied mechanics. In 1930 Sedov graduated from the Moscow State University, where he had been a student of Sergey Chaplygin, with the degree of Doctor of Physics and Mathematical Sciences. He later became a professor at the university. During World War II, he devised the so-called Sedov Similarity Solution for a blast wave. In 1947 he was awarded the Chaplygin Prize. He was the first chairman of the USSR Space Exploration program and broke first news of its existence in 1955. He was president of the International Astronautical Federation (IAF) from 1959 to 1961. Until recently, it had been thought that Sedov was the principal engineer behind the Soviet Sputnik project.
Title: Sergey Sedov
Content:  A native Muscovite, Sedov grew up in a dysfunctional family, both of his parents being alcoholics. Ever since he was a child, Sergey suffered from hearing loss, and at school, he was put in a group for children with special needs. He was described as unsocial, and if he was offended by other children, he would run away, refusing to return to class for several days. His peculiar behavior led to examinations by several doctors in 1989, who concluded that the young Sergey was intellectually disabled. However, they deemed that treatment was unnecessary, as it was believed that he would pose no threat to others around him. 
Title: Sergei Kourdakov
Content:  According to The Persecutor Sergei Kourdakov was born on March 1, 1951, in Novosibirsk Oblast, Soviet Union. His father Nikolai Ivanovich Kourdakov was a soldier in the Soviet Army and a political activist who was a very loyal supporter of Joseph Stalin. He led a brigade in the Winter War and led a unit under General Konstantin Rokossovsky in World War II. After the war, Nikolai helped set up a military base and became the base chief. Although Sergei was told that his father died by being shot, he found out much later from a friend of his father's that when Nikita Khrushchev became Premier of the Soviet Union, he had ordered the elimination of important officers 
Title: Lev Sedov
Content:  He lived separately from his parents after the October Revolution in order not to be seen as privileged. He married in 1925 at the age of 19, and had a son, Lev, the following year. Sedov supported his father in the struggle against Joseph Stalin and became a leader of the Trotskyist movement in his own right.
Title: Lev Sedov
Content:  Just before Adolf Hitler came to power in 1933, Sedov was able to move to Paris where he went to work as a Parisian laborer and became an important activist in the Trotskyist movement. He was frequently followed by agents of the Soviet NKVD. Between 1935 and 1938, while in Paris, Sedov and his partner, Jeanne Martin, also took in and cared for his young nephew, Vsevolod Volkov, called "Sieva" by the family (and who later, in Mexico, took the name Esteban Volkov), the son of Sedov's late half-sister, Zina.

Question: Who is the father of Sergei Sedov?
Answer: Leon Trotsky.
N. Trotsky.
Lev Bronstein.
Lev Davidovich Bronshtein.
Lev Davidovich Bronstein.
Leon Trotski.