Some context: Georg Ferdinand Ludwig Philipp Cantor ( KAN-tor; German: ['geoRk 'feRdinant 'lu:tvIc 'fIlIp 'kantoR]; March 3 [O.S. February 19] 1845 - January 6, 1918) was a German mathematician. He invented set theory, which has become a fundamental theory in mathematics. Cantor established the importance of one-to-one correspondence between the members of two sets, defined infinite and well-ordered sets, and proved that the real numbers are more numerous than the natural numbers.
Cantor's 1874 Crelle paper was the first to invoke the notion of a 1-to-1 correspondence, though he did not use that phrase. He then began looking for a 1-to-1 correspondence between the points of the unit square and the points of a unit line segment. In an 1877 letter to Richard Dedekind, Cantor proved a far stronger result: for any positive integer n, there exists a 1-to-1 correspondence between the points on the unit line segment and all of the points in an n-dimensional space. About this discovery Cantor wrote to Dedekind: "Je le vois, mais je ne le crois pas!" ("I see it, but I don't believe it!") The result that he found so astonishing has implications for geometry and the notion of dimension. In 1878, Cantor submitted another paper to Crelle's Journal, in which he defined precisely the concept of a 1-to-1 correspondence and introduced the notion of "power" (a term he took from Jakob Steiner) or "equivalence" of sets: two sets are equivalent (have the same power) if there exists a 1-to-1 correspondence between them. Cantor defined countable sets (or denumerable sets) as sets which can be put into a 1-to-1 correspondence with the natural numbers, and proved that the rational numbers are denumerable. He also proved that n-dimensional Euclidean space Rn has the same power as the real numbers R, as does a countably infinite product of copies of R. While he made free use of countability as a concept, he did not write the word "countable" until 1883. Cantor also discussed his thinking about dimension, stressing that his mapping between the unit interval and the unit square was not a continuous one. This paper displeased Kronecker, and Cantor wanted to withdraw it; however, Dedekind persuaded him not to do so and Weierstrass supported its publication. Nevertheless, Cantor never again submitted anything to Crelle.
What year was he doing his work on this?
A: In 1878, Cantor submitted another paper to Crelle's Journal, in which he defined precisely the concept of a 1-to-1 correspondence

Some context: DJ Jazzy Jeff & the Fresh Prince was an American hip hop duo from West Philadelphia, Pennsylvania. Rapper Will Smith (the Fresh Prince) met disc jockey Jeff Townes (DJ Jazzy Jeff) in the 1980s, when they were both trying to make names for themselves in West Philadelphia's local hip hop scene. They had as a support live member Clarence Holmes (Ready Rock C) - who was not officially credited to the duo. Holmes left the group in 1990 and later sued unsuccessfully for earnings, claiming a breach of oral contract.
Their 1988 follow-up album, He's the DJ, I'm the Rapper, made them multi-platinum stars. Mostly recorded in the United Kingdom, the album was rap music's first double-vinyl LP release; it was also issued as a single cassette and CD. "Parents Just Don't Understand", the lead-off single, made them MTV household names and also gained the honor of the first Grammy for a hip hop/rap song, which was met with mixed feelings. Nevertheless, the single was a success, launching the group into even more mainstream stardom. The video showed Prince's misadventures of trying to get around his parents' strict rules in a very comical way, very much like their first single "Girls Ain't Nothing but Trouble". It gained much airplay on TV channels such as MTV, giving the group much attention. The song was played in an episode of The Fresh Prince of Bel-Air ("Someday Your Prince Will Be In Effect (Part 1)"), and referenced in two other episodes of the same series ("The Fresh Prince Project" and "Not With My Pig, You Don't"). Another single, "Nightmare on My Street", showcased a fictional confrontation with movie villain Freddy Krueger. Coinciding with the release of the fourth Nightmare on Elm Street film (1988's The Dream Master); New Line Cinema was not pleased. A video allegedly shot for the single was buried, and a disclaimer was hastily included on pressings of the album indicating that the record was not officially affiliated with any of the Nightmare films. (Ironically, Jive Records ended up releasing the soundtrack to the next film in the series, The Dream Child.) After this success, in 1988 the lead singles from Rock the House, including "Girls Ain't Nothing but Trouble", were re-released and changed a bit from their original 1985 release, with the outro referencing singles "Nightmare on My Street" and "Parents Just Don't Understand": Jeff: Man, first your parents just don't understand.Will: Word, I know, man.Jeff: Then you have these crazy nightmares.Will: Why me? Why me? Jeff reveals on track 19 of Skillz's Infamous Quotes mixtape that New Line Cinema approached Will & Jeff for a movie role which they ended up turning down. The film was House Party. The last single from He's the DJ, I'm the Rapper was "Brand New Funk" sampled a James Brown song and quotes it. In the song, the Fresh Prince explains how Jeff has brought in a tape that contains a very cool song that he cannot help but rap over, and how fans react to it. The song was well received by many hip hop fans due to its funk sound, lyrical spins, and the fact that it showed off more of the skills of Jazzy Jeff. The video was shot in black and white, showed live performance clips from a concert and featured 2 Damn Hype Dancing.
was that their most popular
A:
"Parents Just Don't Understand":