I have a C2300 router located in a metal building with poor wifi signal penetration outside of the building to an outdoor wireless camera. The Archer C 2300 router which has three antennas on the device.

I have purchased a Dual Band Wi-Fi mini omnidirectional 5 dBi wall mount outdoor antenna.

My question is does it matter which of the antennas on the unit I replace with the external antenna or do I just simply pick any one of them?