How can the antenna gain improve transmission distances?

The correct choice highlights how antenna gain plays a significant role in improving transmission distances by concentrating energy in a specific direction. An antenna with gain does not radiate energy uniformly in all directions; instead, it focuses the radiated energy, which enhances the signal strength in that particular direction. This directional focus increases the effective radiated power (ERP) in the intended path, thereby improving the transmission range and overall communication reliability between the transmitter and receiver.

When energy is directed where it is needed most, it can overcome obstacles, reduce loss from spreading out, and improve the chance of successful signal reception. This is particularly crucial in long-distance communications, where larger distances or physical barriers could otherwise weaken the signal.

On the other hand, overlapping frequencies, diluting signals, or simply boosting signal strength are not effective methods for improving transmission distances in the context of antenna gain. Overlapping frequencies can lead to interference; diluting signals does not contribute to their strength but rather diminishes the effectiveness; and merely boosting overall signal strength without considering the directionality would not achieve the focused advantage that high-gain antennas provide.