As part of a scrum team, the scrum master reviews the work done at the end of each sprint to ensure it is valuable to the customer. Once it goes through this review, it can go to the customer. What is the challenge with this approach?

It will be difficult for the scrum master to understand all the technical$-$challenges.

The scrum master might take too much time evaluating the product.

The product owner determines what's valuable to the customer.

The scrum master should work closely with the senior developer to make this determination.