Option 1 states that the only quantity transmitted through the medium is the material of the medium itself. This option is incorrect because, in a longitudinal wave, both the material particles and the energy are transmitted through the medium. The material particles vibrate back and forth in the same direction as the wave, allowing the wave to propagate through the medium.

Option 2, which is the correct answer, states that only the energy is transmitted through the medium. This is true because in a longitudinal wave, the energy is transferred from one particle to the next as they vibrate. The particles do not move with the wave but rather oscillate around their equilibrium positions.

Option 3 suggests that both the material of the medium and the energy are transmitted through the medium. Although the material particles do play a role in the transmission of the wave, it is more accurate to say that the energy is the main quantity transmitted.

Option 4 states that none of the above is correct. This is incorrect, as option 2 correctly identifies that the quantity transmitted through the medium in a longitudinal wave is the energy.