Choose the correct statement w.r.t the diagram shown below: A: When a stimulus is applied at a site A on the polarised membrane, the membrane at the site A becomes freely permeable to potassium ions. B: The polarity of the membrane at site A is thus reversed upon giving a stimulus and hence depolarised state is achieved.

Step-by-step solution

When a stimulus is applied at a site on the polarised membrane, the membrane at the site A becomes freely permeable to Na+. This leads to a rapid influx of Na+ followed by the reversal of the polarity at that site, i.e., the outer surface of the membrane becomes negatively charged and the inner side becomes positively charged. The polarity of the membrane at the site A is thus reversed and hence depolarised.