1. (2019高二下·嘉兴期末) 有如下VB程序段：

Dim a(1 To 10) As Integer, b(5 To 10) As Integer

a(1) = 71: a(2) = 73: a(3) = 90: a(4) = 79: a(5)  = 76

a(6) = 88: a(7) = 91: a(8) = 84: a(9) = 100: a(10) = 80

For i = 10 To 1 Step -1

  b((a(i) - 1) \ 10) = b((a(i) - 1) \ 10) + 1

Next i

该程序段运行后，数组元素b(7)的值是（  ）