The correct option is C Truism
A truism is a statement that is obviously true and says nothing new or interesting. For example, "the truism that you get what you pay for". Hence, Option C is correct. Among the rest of the options, proverb means a short, well-known pithy saying, stating a general truth or piece of advice, precept means a general rule intended to regulate behaviour or thought, formula means a mathematical relationship or rule expressed in symbols. These options do not express the intended meaning, hence incorrect.