The time period being referred to is the sensitive period. This time period is also referred to as the critical period. The importance of a critical period is such that it must involve certain stimuli from which an organisms learns and acquires traits. If some of these stimuli are not present in the critical period, the organism has difficulty acquiring the trait or skill, and may even find it to be impossible to learn the skill.
Answer: adaptive immune response
Explanation:
Autoimmune disorders are caused by different microoorganism and drug which manipulates the immune system in a way that immune system become unable to recognise between self antigen and foreign antigen. In that case immune system treats foreign antigen as self antigen which cause systemic or organ specific damage.
The exact cause of autoimmune disorders is unknown and hence it is thought that it is caused by adaptive immune response which builds against self antigens and causes damage to the cells.
Hence, some autoimmune disorders are thought to be caused by adaptive immune response.
The answer is A, convergence.
