Plain or self-evident truth

A. Proverb

B. Precept

C. Truism

D. Formula

Answer: Option C

Solution(By Examveda Team)

One word substitute is Truism.

Proverb: a short, well-known pithy saying, stating a general truth or piece of advice.
Precept: a general rule intended to regulate behaviour or thought.
Truism: a statement that is obviously true and says nothing new or interesting.
Formula: a mathematical relationship or rule expressed in symbols.