Existentialist texts suggest that

a)the family unit has lost its cohesiveness due to the effects of industrialization
b)individuals must strive to live authentically in an otherwise meaningless world
c)most people are not capable of recognizing the divide between mind and body
d)the natural world has been defiled by the immorality of human beings

Answer:

Existentialist texts suggest that B) individuals must strive to live authentically in an otherwise meaningless world

Explanation:

The word "existentialism" was thought by Gabriel Marcel, the French Catholic philosopher. It basically suggests that each individual is an independent individual responsible for his acts. It is what they think they are and not what others think about them.  

It doesn’t mean that individual can do whatever they wish, it means one should think big and be free. One should do some work that one loves to do. Existentialism largely believes in authenticity in whatever an individual does.

an expression designed to call something to mind without mentioning it explicitly; an indirect or passing reference.