102865
Many of the political rides have their roots from Critical Mass and are often described or categorized as a form of political protest , street theatre , party-on-wheels , streaking , public nudity and clothing-optional recreation ; thus , they attract a wide range of participants .
 Critical Mass
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
Answer:
 Critical Mass