Refer to the exhibit. A company wants to connect two new offices to their main office. One building is 2 miles away from the headquarters and the other is 12 miles away. The angle between the buildings is 80 degrees. Which antenna is the best to use in this situation?

A.
12 dBi omni

B.
10dBiyagi

C.
14dBi sector

D.
21dBi dish

Explanation:
http://www.cisco.com/en/US/prod/collateral/wireless/ps7183/ps469/product_data_sheet09186a008008883b.html :
Parabolic dishes have a very narrow RF energy path, and the installer must be accurate in aiming these types of antennas these at each other.
Ex.
14 dBi Mast Mount Sector : Azimuth 3dB Beamwidth 90 degrees
21 dBi Mast Mount Parabolic Dish : Azimuth 3dB Beamwidth 12 degrees
10 dBi Wall/Mast Mount YAGI : Azimuth 3dB Beamwidth 55 degrees
12 dBi Mast Mount Omnidirectional : Azimuth 3dB Beamwidth Omnidirectional 360 degrees