Weird SQL Server Management studio behavior

Select
    colA,
    colB,
    colC
    colD
From
    table1

colC as colD

Select
    colA
    , colB
    , colC
    colD
From
    table1

Select
    colA,
    colB
    colC
    colD
From
    table1

Select
    colA,
    colB,
    colC,
    colD,
From
    table1