The heights of tansmitting and receiving antennas are respectively $\frac{1}{20000}$ and $\frac{1}{80000}$ times the radius of the earth. The maximum distance between these two antennas for satisfactory communication in line of sight mode is (Radius of the earth $=6.4 \times 10^6 \mathrm{~m}$ )

• A

  48 km
• Correct answer
  B

  96 km
• C

  320 km
• D

  192 km

Hence, the correct answer is option: 'B'.