What are two likely causes for a DRS cluster to become unbalanced? (Choose two.)

A lower migration threshold makes DRS more conservative and requires a larger imbalance before recommending migrations, but DRS will still act once that threshold is exceeded - it does not permanently prevent rebalancing.

VM-to-host affinity or anti-affinity rules restrict which hosts a VM can run on, so even when DRS identifies that a VM should be migrated to a less-loaded host, the rule violation blocks the recommendation and leaves the cluster unbalanced.

A locally attached device such as a CD-ROM ISO or USB device makes a VM non-migratable via vMotion, so DRS cannot move that VM regardless of the load imbalance it contributes to.

Migration cost is not an administrator-configurable DRS parameter; DRS calculates migration cost internally as part of its algorithm and no setting labeled 'migration cost' can be set too low to cause imbalance.