1Q:
Lets split the years into two half
pre-expansion: 2001-2003
The highest avg attendance % during this time is around 80-85% in 2003
Post-expansion: 2004-2005
The highest avg attendance % during this time is around 75-80% in 2005
Note that the question asks about average attendance and not for average attendance %.
Now comparing between 2003 and 2005:
The avg number of people attending a game in 2003 = 60000*0.8 to 60000*0.85 = 48000 to 51000
The avg number of people attending a game in 2005 = 90000*0.75 to 90000*0.80 = 67500 to 72000
Hence the highest average attendance occurred in 2005.
Option D2Q:
Since the number of games per season need not be constant, we won't be able to determine a solution for this.
For ex:
2003 season could have had 10 matches, while 2005 season had only 1 match. So net attendance will be higher in 2003 than 2005. But if both the season had equal matches, the net attendance in 2005 would be higher.
Hence
Option D.
3Q:
Now comparing between 2003 and 2004:
The average attendance % in 2003 = 80-85%
The average attendance % in 2004 = 55-60%
The avg number of people attending a game in 2003 = 60000*0.8 to 60000*0.85 = 48000 to 51000
The avg number of people attending a game in 2004 = 90000*0.55 to 90000*0.60 = 49500 to 54000
If we take average of range in 2003 = (48000+51000)/2 = 49500
If we take average of range in 2004 = (49500+54000)/2 = 51725
% increase of attendance in 2004 = (51725-49500)*100/49500 = ~4.5%
Since 4.5% is not greater than 5%, we choose
Option C.