To determine which column is greater, let's simplify the expressions in each column.
Column A: (3t+4r)/rt
Column B: (3t+4r)/(r+t)
To compare the two columns, we can cross-multiply and compare the resulting expressions.
For Column A:
(rt) * (3t+4r) = 3t^2r + 4r^2
For Column B:
(r+t) * (3t+4r) = 3t^2 + 7rt + 4r^2
As we can see, the expressions in Column A and Column B are not equal. Therefore, we cannot determine which column is greater without additional information.
Hence, the correct answer is D.