Open assessment: Length of a Sprint

Why would any risks and events presented by business not be considered as well? If a team fails to take these matters into consideration when determining Sprint length, what might the consequences be?

The correct answer is D, all of the above... So C is partially correct

A) Short enough to keep the business risk acceptable to the Product Owner.

This is true, if you are in a rapidly highly dynamic environment, a month could even be too long. You want your sprint length to bring you value as soon as possible. Values also comes from reducing risk. Risk for instance, that the competition delivers some key feature before you do. But also risk to miss valuble customer feedback, if your feedback loops are not short enough. So this answer is correct.

B) Short enough to be able to synchronize the development work with other business events.

Sure, if there is no cadence or alignment with (external) events, you could be in trouble. Just as an example, lets say Nexus business stakeholders have a Podium event every 3 weeks, where the fully integrated new increment is presented and reviewed. If you go for a 4 week sprint, you would not be in line with this, and it will be hard to review your increment. So from a business and practical point of view, this is true

C) No more than one month.

As you already deducted, this answer is true as well

Some more from the Scrum Guide in the section that describes the Sprint (any emphasis is added by me):

Sprints are limited to one calendar month. When a Sprint’s horizon is too long the definition of what is being built may change, complexity may rise, and risk may increase. Sprints enable predictability by ensuring inspection and adaptation of progress toward a Sprint Goal at least every calendar month. Sprints also limit risk to one calendar month of cost.

There is more than one element to determining the length of the sprint.  Answers A) and B) speak to the part I highlighted above. @Ian's questions and @Xander's elaboration are excellent insights. 

There are a lot nuances to the Scrum Guide. I reread it frequently, sometimes as often as weekly, and every time I pick up something that I missed before. 

Great! 

Thank you ALL for your guidance. It does make sense now. I have to read the Scrum Guide with new eyes. 

Thanks again, 

I have to read the Scrum Guide with new eyes. 

I still do that from time to time, it is part of the continuous improvement cycle ;)

@Xander Ladage I did and it worked!! 

Now time to learn more!! 

Thanks