A function $f: \mathbb{R} \rightarrow \mathbb{R}$ defined by $f(x)=\left\{\begin{array}{c}2 x+3, x \leq \frac{4}{3} \\ -3 x^2+8 x, x>\frac{4}{3}\end{array}\right.$ is

• A

  One-one function
• Correct answer
  B

  not onto
• C

  a bijective function
• D

  constant function

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