Which word makes the truest sentence? a man is always to his son?

The correct answer is "Related".

Explanation:  

In terms of grammar, we call a true sentence to that sentence that is factually correct. In that sense, the word "related" makes the sentence the truest one and it is more accurate to use that one. In terms of social, the word "related" makes the connection between the two people who are family.

productive most commonly means: achieving or producing a significant amount or result.

explanation:

productive can also mean:

these depend on how the word productive is used. most likely productive will mean   achieving or producing a significant amount or result.

chavez's example shows that nonviolent protest can work well. it shows that one nonviolent man can stop a mob, which proves chavez's point and persuades people to protest nonviolently.