The CA is stored in the AD, which allows it to be sent to all the clients (i.e. computers) present in the domain.
In the ADCS server, you can open ADSI Edit
Then connect to the “Configuration” partition

By exploring the tree structure :
- CN=Configuration,DC=labad,DC=en
- CN=Services
- CN=Public Key Services
- CN=Certification Authorities
- CN=Public Key Services
- CN=Services
We find the CA.