Answer:
These are for the WiFi. On a few cards, the Bluetooth facility is being provided through the second antenna, and that is 2.4 GHz, and hence both the antennas are the same in length. And the 5 GHz comes with the wavelength which is half of that of 2.4 GHz, and this is you can use both the antennas for any out of the two frequencies and you can connect to only one Wi-Fi network at one time, however, it needs the second antenna to communicate with any device which is of type Bluetooth, and two at a time.
Explanation:
The answer is self explanatory.