c
Pressure is maximum at closed end and minimum at open end.
At $x=0 m, \cos \frac{3 \pi x}{2}=\cos \frac{3 \pi \times 0}{2}=1$
Thus $p$ is maximum, so $x=0$ is a closed end
At $x=2 m \cos \frac{3 \pi x}{2}=\cos \frac{3 \pi \times 2}{2}=-1$
Thus $|p|$ is maximum at $x=2 m,$ so $x=2$ is also a closed end.
Hence the given organ pipe is closed at both ends and length of the pipe is $2 m$