Least common multiple of $8,12$ and $20$ is ________ .

The correct option is C $120$

$8=2\times 2\times 2$

$12=2\times 2\times 3$

$20=2\times 2\times 5$

Therefore LCM of $8,12$ and $20$$=2\times 2\times 2\times 3\times 5=120$