In a Column Splice Detail, a Butt Plate Is Required

In a column splice detail, a butt plate is required when

A) the upper- story column is much larger in height than the lower- story column.
B) the upper- story column is the same height as the lower- story column.
C) the upper- story column has the same cross- sectional dimensions as the lower- story column.
D) the upper- story column is much smaller in height than the lower- story column.
E) none of the above.