A focus group is currently made up of x red balls and y green balls. If 5 red balls and 4 green balls are added to the group, and if one ball is selected at random from the larger focus group, then what is the probability that a red ball is selected?  Choose the correct choice from the following options:
A) x/(x + 4)  B) y/(x + 5)  C) (x + 5)/(x + y + 9)  D) (y + 4)/(x + y + 9)  E) (x + 4)/(x + y + 9)
x red balls   y green balls   x+4+y+5 is the total   =x+y+9   x+5 is the number of red balls   so (x + 5)/(x + y + 9)   the answer is (x + 5)/(x + y + 9)
<result>C</result>
A focus group is currently made up of x red balls and y green balls. If 5 red balls and 4 green balls are added to the group, and if one ball is selected at random from the larger focus group, then what is the probability that a red ball is selected?