Last week, Newtown Plastics announced that it had developed a new plastic container that is stronger and more durable, yet easier to recycle. In response to this announcement, the firm's stock price rose from $$21$ a share to a high of $$27$ a share and has remained at that level. This is an example of a$($n$)$

A$)$ overreaction and correction.

B$)$ efficient market reaction.

C$)$ pre$-$activity action.

D$)$ post$-$activity reaction.