Answer:b)Tacit knowledge
Explanation: Tactic knowledge is considered as the informal form of knowledge. It is supposed to be a knowledge that is difficult to be transferred from one person to other.This knowledge cannot be easily understood by the person in written or verbal form.
Tactic knowledge is mostly understood clearly by the source person or port.Other option given are just a simple form of knowledge which can be understood easily. Thus the correct answer is option(b).