The right answer is 2 and 3.
The applications of spectroscopy are very diverse; they are in many areas: fundamental physics, astrophysics, nuclear physics, plasma physics, solid state physics, materials science, metrology, microelectronics, new light sources, laser isotope separation, and so on. The R.M.N. provided a very powerful medical imaging technique. Other analysis techniques are similar to spectrometry, in the sense that a spectrum is measured as a function of energy or frequency. Acoustic spectroscopy concerns pressure vibrations for which the notions of frequency and wavelength are similar, although the phenomenon is of a nature quite different from electromagnetic waves. Here again, the frequency range extends far beyond the audible frequency range, from infrasound to ultrasound. Mass spectrometry produces spectra as a function of the mass-to-electric charge ratio of atomic or molecular ions.