104
zero
122 different players have had a total of 295 40-HR seasons.
he hit 15 home runs in his rookie season.
Darrell Evans hit 41 home runs with the 1973 Atlanta Braves (NL), and 40 home runs with the 1985 Detroit Tigers (AL). He was the first (I checked all players with 40 home run seasons before 1985).
Yastrzemski, Carl (1)
25 players
As many as the players can hit. There is no limit.
25
As of 2009, 125 players have hit 300 or more career homer runs in the Major leagues..
2 players hit 40 or more home runs in 2008, both from the National League. R. Howard(47), and A. Dunn (40)
5
Nobody did
zero
It would score 4 (four) runs.
Many MLB teams have scored runs with multiple players in the same inning. Many MLB teams have also had multiple home runs by different players occur in the same inning, including teams like the Yankees, Blue Jays, and Red Sox.
1500
122 different players have had a total of 295 40-HR seasons.