Experimentation can help a Product Owner to: Select all that apply

The Developers have struggled to get all of their forecasted work done during the last three Sprints. As a Product Owner what steps could you take to help the Developers improve their ability to deliver a done Increment? (choose the best two answers)

Negative value can be in the form of _________(choose ALL that apply)

Which two statements are the most accurate in regards to scaling Scrum for large projects that require multiple Scrum Teams? (choose the best two answers)

Your organization uses NPS (Net Promoter Score) measures to understand your customers' satisfaction levels. Your team had invested a lot of time and effort creating and delivering a release that included many new product features. After a few months, you see that the NPS score did not improve.
What other measures can help you to better understand this outcome? (choose the best two answers)