confused on knowing what type of test to perform :

A psychologist has performed the following experiment. For each of 10 sets of identical twins who were born 30 years ago, he recorded their annual incomes according to which twin was born first. The results (in $1,000s) are shown below. Can he infer at 5% significance level that there is a difference in income between the twins?

First born

32

36

21

20

49

27

39

38

56

44

Second born

44

43

28

39

51

25

32

42

64

44

What is the appropriate test to perform?

• Paired test.H₀:_D0versusH_a:_D=0
• Paired test.H₀:_D=0versusH_a:_D0
• Paired test.H₀:_D=0versusH_a:_D>0
• Two-sample test.H₀:₁=₂versusH_a:₁<₂
• Two-sample test.H₀:₁₂versusH_a:₁=₂
• Two-sample test.H₀:₁=₂versusH_a:₁₂
• Paired test.H₀:_D=0versusH_a:_D<0
• Two-sample test.H₀:₁=₂versusH_a:_1>2