Where can you find out how many overall and used licenses your company have for Salesforce?

Answer options:

A.Company Information
B.Company Settings
C.Default Settings
D.Assign Licenses

Correct Answer: A 
From Setup, enter Company Information in the Quick Find box, then select Company Information. The Company Information page shows all the important information about your company (listed here in alphabetical order). 
Option B is incorrect because within Salesforce we don’t have company settings, we have company profile or company information. 
Option C is incorrect because within Salesforce we don’t have default settings but there is sharing settings and organization-wide sharing default. 
Reference: 

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