Propaganda is
a. a memorial, a lasting remembrance, evidence.
b. something created to deliberately convince or influence people's thoughts, opinions, and/or actions.
c. the art of using symbols, or having symbolic meaning.
d. a recurring element in a work of art that provides an effect mode of social protest.

The question is asking us what propaganda is, and we have a number of options. Propaganda is basically a bias in information - for example the governments use propaganda to convince their citizens of certain facts. They can use for example posters or radio. Therefore, the correct answer is b. something created to deliberately convince or influence people's thoughts, opinions, and/or actions.

So you know what happened and so it doesn’t repeat it’s self