Gestures and body language fall under the category (sphere) of which is one of the categories under the larger sphere of
a) self-expression; experiential knowledge of pab) self-efficacy; professional knowledge of pac) self-expression; theoretical knowledge of pad) self-sufficiency; experiential knowledge of pa

option A

Explanation:

For developing good relationship either personal or professional level, only good communication or good words are not enough, the way you express your point means your nonverbal communication like body language matters the most. Body language means your behavior, manners and your expressions. Your gesture like the way you response and in what tone and your physical contact with others have strong impact.  

ι вєℓινє тнє αиѕωєя тσ уσυя qυєѕтισи ιѕ в. ℓуѕσѕσмє

ι нσρє тнαт ι ¢συℓ∂ нєℓρ уσυ.