It is important to know that the domain refers to the set of x-values of the given function.
The first interval shown is
![(-\infty,-6\rbrack](https://img.qammunity.org/2023/formulas/mathematics/high-school/jkv4j1qsl05yp6ztg0l1n3kejp2l7uauxp.png)
The second interval shown is
![(-6,-3)](https://img.qammunity.org/2023/formulas/mathematics/high-school/88vkdrcn1qhsy4q9ilcncryj6y8dnz3yxf.png)
The third interval shown is
![\lbrack-3,4\rbrack](https://img.qammunity.org/2023/formulas/mathematics/high-school/84g6h6ihn1q40mdco9zaeyk423p1cfd0c6.png)
If you add all the intervals shown, we get the following domain
![(-\infty,4\rbrack](https://img.qammunity.org/2023/formulas/mathematics/high-school/s3cpncqqd6q1jr80byhwiy2ryrxlxjgn6o.png)
Which can be expressed as
![x\leq4](https://img.qammunity.org/2023/formulas/mathematics/college/1trsl8xd0d0ehtgg82voouruxwqlteawz2.png)
Hence, the answer is C.