Answer
Pipe A has two open ends.
Work Step by Step
Note that $~~1.2 = \frac{6}{5}$
We can write an expression for the frequencies in a pipe that is open at both ends:
$f = \frac{nv}{2L},~~$ where $~~n = 1,2,3,...$
Therefore, the two frequencies must be the fifth and sixth harmonics of a pipe with two open ends.
Pipe A has two open ends.
