Option Explicit
Sub TEST()
Dim Brr, Crr, Y, i&, X&, T$
'↑宣告變數
Brr = Range([B2], [A65536].End(xlUp))
'↑令Brr變數是二維陣列,以儲存格值帶入
ReDim Crr(1 To UBound(Brr), 1 To 1)
'↑宣告Crr變數是二維空陣列,縱向同Brr,橫向1欄(1到1)
For i = 1 To UBound(Brr)
'↑設順迴圈!
If Brr(i, 1) = 1 And (X > Brr(i, 2) Or X = Empty) Then X = Brr(i, 2)
'↑如果A:A有1 令X變數是 B:B的資料的最小值
Next
For i = 1 To UBound(Brr)
'↑設順迴圈!
If Brr(i, 1) = 1 And Brr(i, 2) = X Then Crr(i, 1) = 1
'↑處理B:B的資料是最小值的! 在C:C標示 1
Next
[C2].Resize(UBound(Crr)) = Crr
'↑令Crr陣列值寫入儲存格
Set Y = Nothing: Erase Brr, Crr
End Sub