A: In general, YES!
For OSS, the license terms are written in its OSS license.
You are free to use it, including product use, as long as you follow the OSS license conditions.
If the OSS license is approved by OSI, you can use it commercially, but in other cases, you need to check the conditions. See OSI (https://opensource.org/) for more information.
In case you are not sure, use TrustSource DeepScan to review the source repository (or repositories) to determine the complete license stack associated to that component. You also may scan the component within your build and use the automated analysis using TrustSource LegalCheck to determine all resulting obligations.
This answer has been originally provided by the OpenChain Japan workgroup and was extended by TrustSource.