A manager wants to see if it worth going back for a MBA degree. They randomly sample 18 managers' salaries before and after undertaking a MBA degree and record their salaries in thousands of dollars. Assume Salaries are normally distributed. Test the claim that the MBA degree, on average, increases a manager's salary. Use a 10% level of significance.

t-Test: Paired Two Sample for Means
	New Salary	Old Salary
Mean	61.878	56.999
Variance	177.5551	115.8012
Observations	18	18
Pearson Correlation		0.7464
Hypothesized Mean Difference		0
df		17
t Stat		2.9870
P(T<=t) one-tail		0.0024
t Critical one-tail		1.3334
P(T<=t) two-tail		0.0048
t Critical two-tail		1.7396

The hypotheses for this problem are:

H₀: _D = 0

H₁: _D > 0

What is the correct test statistic?

2.9870
1.3334
1.7396
0.7464