How many opportunity big deal alerts can a Salesforce Admin create for the organization?

Answer options:

A.One
B.Two
C.Three
D.Four

Correct Answer: A 
You can only activate one opportunity alert for your Salesforce org. 
Other options are incorrect because you can only activate one alert. You cannot activate more than one alert. 
Reference: 

https://help.salesforce.com/articleView?id=activating_big_deal_alerts.htm&type=5