d. Inform the Product Owner
e. Take a call to remove some of the Sprint Backlog Items
Reasoning
As we are still in the Sprint Planning meeting i.e. haven’t started the Sprint yet, the developers are free to make changes to the Sprint Backlog items. They can choose to remove some of the items which they think that cannot be completed with the current Development Team’s capacity.
Note that addition or removal should always be done in consensus with the Product Owner as he is the one who decides on the Priority of these items. The removal is not allowed once the Sprint has started.