Final answer:
An Omnidirectional antenna is used in WLAN design, radiating power equally in all horizontal directions and having a theoretical gain of 0 dBi. Option A is correct.
Step-by-step explanation:
The antenna type referred to in wireless LAN (WLAN) design that is a theoretical antenna which radiates an equal amount of power in all directions (in a spherical pattern) and is said to have a gain of 0 dBi is an Omnidirectional antenna.
This type of antenna produces a radiation pattern that is roughly spherical in shape, so the transmission is equally strong in all directions (horizontally), with the gain typically being measured in comparison to a hypothetical isotropic radiator. Such antennas are commonly used in Wi-Fi routers and wireless access points for providing uniform coverage.
The antenna type that is theoretical and radiates an equal amount of power in all directions is called an omnidirectional antenna. This type of antenna has a gain of 0 dBi, which means it does not amplify or focus the signal in any specific direction. It radiates the signal equally in all directions, forming a spherical pattern.
An example of an omnidirectional antenna is a whip antenna commonly used in Wi-Fi routers.