An insurance company selected samples of clients under 18 years of age and over 18 and recorded the number of accidents they had in the previous year. The results are shown below.

Under Age 18	Over Age 18
n1 = 600	n2 = 500
Number of accidents = 228	Number of accidents = 120

We are interested in determining if the accident proportions differ between the two age groups. The value of the test statistic is _____.

a. 0.44

b. 3.39

c. 5.09

d. 4.97