As given by the question,
There are given that the expression
![\sqrt[]{-72}](https://img.qammunity.org/2023/formulas/mathematics/college/1zsgbynjna09u69wdzchw1u2jo8qrzqhbx.png)
Now,
From the concept of radical rule:
![\sqrt[]{-a}=\sqrt[]{-1}\sqrt[]{a}](https://img.qammunity.org/2023/formulas/mathematics/college/3iecz927xinh9xtxgw3z9u3ey2fsnqc6dd.png)
Then,
Apply the above radical rule into the given function
![\sqrt[]{-72}=\sqrt[]{-1}\sqrt[]{72}](https://img.qammunity.org/2023/formulas/mathematics/college/hopkuk0vn27ug23j157zdw7ewb9a0h8p95.png)
Now,
From the concept of imaginary number rule:
![\sqrt[]{-1}=i](https://img.qammunity.org/2023/formulas/mathematics/high-school/6auedmvsax8nlo4hpms2kngcv15a6lmlel.png)
Then,
Apply the above rule into the given expression
![\begin{gathered} \sqrt[]{-72}=\sqrt[]{-1}\sqrt[]{72} \\ \sqrt[]{-72}=i\sqrt[]{72} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/hdxci9iuset3o43mzukhscxy275zj6lo8w.png)
Now,
![\begin{gathered} \sqrt[]{-72}=i\sqrt[]{72} \\ \sqrt[]{-72}=6i\sqrt[]{2} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/obacz2xnm3tn9v2ufesj69qfmwn6a058x1.png)
Hence, the correct option is A.