Answer
Option $I$
Work Step by Step
The given inequality is "$x$ is greater than or equal to $-6$".
The numbers included in this set are the numbers that are greater than or equal to $-6$.
The equivalent interval notation of the given inequality will have:
$\bf\text{lower limit:}$
$-6$, a bracket will be used since $-6$ is included
$\bf\text{upper limit:}$
none, so positive infinity will be used
Therefore, the interval is: $\color{blue}{[-6, \infty)}$