Which of the following is not an aggressive periosteal reaction?

Ans. is 'c' i.e., Thick and irregular Periosteal reaction* Periosteum is dense layer of specialized connective tissue which invests the outer bony cortex except at the articulating surfaces of synovial joints.* Direct or indirect insult to the periosteum causes it to elevate from the underlying bony cortex. This causes a nonspecific radiological finding called periosteal reaction. Following table depicts the different types of periosteal reactions.Types of periosteal reactionNon-aggressiveThin Solid Thick and irregular SeptatedAggressiveSpiculated Hair-on-end Sunburst Laminated Disorganised Interrupted Codman triangle