Which of the following is a prime number? A. $153$ B. $142$ C. $135$ D. $196$ E. $127$E. $127$

Show AnswerShow The First Step1. If the sum of each digit in three digit number is a multiple of $9$, then the number is a multiple of $9$. This is one of basic number theory that a number is divisible by $9$ if the sum of each digit number is a multiple of $9$. So, $153$ is not a prime number.Show Next Step2. If the digit in one's place is either $0$ or $5$, then the number is a multiple of $5$. So, $135$ is not a prime number.Show Next Step3. $142$ is a multiple of $2$ since it is an even number. So, it is not a prime number. $196$ is a square of a number. So, it is not a prime number. Therefore, $127$ is a prime number. No More Steps