What is the greatest prime factor of (10!9!) + (10!11!)?  Choose the correct choice from the following:
A) 23
B) 29
C) 31
D) 37
E) 41
10!9! + 10!11!   = 10!9! (1+10*11)   = 12!11!(111)   = 12!11!(3*37)   The greatest prime factor is 37.   The answer is 37.
<result>D</result>
What is the greatest prime factor of (10!9!) + (10!11!)?