Question

the internet and social media have increased the level of interactions between politicians and citizens, but how has their use changed the nature of the interactions? their use has required citizens to be proactive. their use has structured the nature of the interactions. their use has increased the formality of the interactions. their use has made interactions more volatile.

Explanation:

With internet and social - media, citizens can initiate interactions with politicians, thus being more proactive. Other options like structuring, increasing formality or making interactions more volatile are not the main changes in nature of interactions.

Answer:

Their use has required citizens to be proactive.