Which of the following is a simple sentence? a. many are called, but few are chosen b. a penny saved is a penny earned. c. fools rush in where angels fear to tread. d. if at first you don't succeed, try, try again.

The answer is: B. A penny saved is a penny earned.  

A simple sentence consists of an independent clause that can stand on its own because it expresses a complete thought. A clause is usually formed by subject, a verb and sometimes a complement.

In the example sentence, "A penny saved" is the subject, "is" is the verb and "a penny earned" is the complement.

The sentence which is simple is B: A penny saved is a penny earned.

Explanation:

This is because a simple sentence is a sentence which consists of one simple independent clause with a subject and a verb.  

From the choices given B is the only sentence with only one independent clause.

A consists of two clauses (1. Many are called, 2. but few are chosen); C also has two clauses (1. Fools rush in, 2. where angels fear to tread) and D as well (1. If at first you don't succeed, 2. try, try again).  

i think the literacy device is "it's frozen head"