Which of the following frequency ranges is most suited for meteor-scatter communications?

Meteor-scatter communication relies on bouncing radio signals off the brief, highly ionized trails left by meteors burning up in the E region of the ionosphere. The physical properties and ionization density of these trails reflect frequencies in the upper HF and lower VHF ranges most efficiently. The frequency range of 28 MHz to 148 MHz, which includes the 10-meter, 6-meter, and 2-meter amateur bands, is the 'sweet spot' for this propagation mode. Lower HF frequencies are less dependent on meteor scatter for propagation, while UHF frequencies (like 220 MHz and 450 MHz) require much denser ionization than typical meteor trails provide to reflect effectively.