Which of the following compounds possesses a chiral centre?

The molecule $3$-penten- $2$ -ol can exhibit:
$\left(\mathrm{a}\right)$ Optical isomerism
$\left(\mathrm{b}\right)$ Geometrical isomerism
$\left(\mathrm{c}\right)$ Metamerism
$\left(\mathrm{d}\right)$ Tautomerism

The correct answer is:

The following two compounds

  and  are