Well we can do this by checking the value of each radical.
A. = [tex] \sqrt{166} [/tex] = 12.88 (this is too much)
B. = [tex] \sqrt{83} [/tex] = 9.11 (this is too little)
C. = [tex] \sqrt{105} [/tex] = 10.24 (this is PERFECT!)
D. = [tex] \sqrt{95} [/tex] = 9.74 (this is too much)
The reason why radical 105 is perfect is because it is between 10 and 11 just like the question asks.
SO YOUR ANSWER IS C
