question: What is the main difference between beam steering and beam focusing? option 1: Beam steering controls the relative angle of the transmitted signal, while beam focusing also controls the depth along the direction of propagation. option 2: Beam steering controls the depth along the direction of propagation, while beam focusing controls the relative angle of the transmitted signal. option 3: Beam steering and beam focusing are the same thing. option 4: Beam steering and beam focusing are both techniques used in conventional far-field communications. option 5: Beam steering and beam focusing are both techniques used in radiating near-field communications. 