List-I shows four configurations made of straight and semi-circular narrow tubes containing air. A sound wave of wavelength $$\lambda=0.29\,\mathrm{m}$$ enters these structures at the point $$S$$ and a sound detector is placed at $$D$$. Between the points $$S$$ and $$D$$, the sound travels only through the tubes. List-II contains the possible smallest values of $$l$$ (refer to the figures) for which the detector $$D$$ records maximum amplitude. Ignore effects of sharp corners. [Given $$\cos(15^\circ)=0.97$$]

Choose the option that best describes the match between the entries in List-I to those in List-II.