If the point $P\left(\frac{3a}{2},1\right)$ lies between the two different lines $x+y=a$ and $x+y=2a,$ then the least integral value of $\left|a\right|$ is equal to

• A

  $1$
• B

  $2$
• Correct answer
  C

  $3$
• D

  $4$

Hence, the correct answer is option: 'C'.