Joining organizations to work towards a common goal is the best example of vital engagement.
Step-by-step explanation:
The concept of vital engagement refers to an environment and lifestyle that promotes personal involvement, belonging, responsibility, challenge, comradeship, and love. From the given options, the best example that demonstrates vital engagement is joining organizations to work together towards a common goal. This helps individuals become attached to their communities and politically engaged, as discussed by Robert Putnam in his book "Bowling Alone."