Suppose we wish to testH0:12 0 versusHA:12> 0. Independent random samples are taken from two normally distributed populations with unknown variances. The following sample statistics are given:X11= 15.4,X2= 14.5,s1= 2,s2= 2.28,n1= 35,n2= 18. Assuming that the population variances are not equal, what is the value of the appropriate test statistic?

a. 1.73

b. 1.61

c. 1.12

d. 1.42

e. 2.01