Answer:
Option B
Explanation:
In simple words, externality refers to the situation when an individual party gets affected by the decisions or actions of some one or more party. If such effects works for the betterment of the affected party than its is called positive externalize and if it results in deterioration of the affected pastry than it is called negative externality.
Thus, from the above we can conclude that the given case deficits negative externality as now we have to face the problem of heavy traffic.