What do changes made to resources available in a parent pool affect in a resource pool hierarchy?

What do changes made to resources available in a parent pool affect in a resource pool hierarchy?

A.
Child pools

B.
Sibling pools

C.
Sibling and child pools

D.
Root resource pools

Explanation:
Page 45 from vsphere-esxi-vcenter-server-50-resource-management-guide.pdf

A resource pool can contain child resource pools, virtual machines, or both. You can create a hierarchy of shared resources. The resource pools at a higher level are called parent resource pools. Resource pools and virtual machines that are at the same level are called siblings. The cluster itself represents the root resource pool. If you do not create child resource pools, only the root resource pools exist.