What are the customization limitations that are available for the Salesforce admin in the Salesforce mobile app that he doesn’t encounter through the website? (Choose 2 options)

Answer options:

A.Salesforce admin can add more than 30 components to a lightning page region
B.Custom Images that are used for action icons should be less than 3 MB
C.Salesforce mobile app does not support login rerouting to other salesforce apps
D.On Click, JavaScript buttons are not supported in the Salesforce mobile app

Correct Answer: C and D 
Salesforce mobile app doesn’t support login rerouting to other salesforce apps or even to any custom home tabs. It is very essential to turn off the mobile web in case this rerouting is needed. In addition to this, Custom buttons that express the content source as On Click JavaScript are not supported in the Salesforce mobile app. 
Option A is incorrect because you don’t have the ability to add more than 25 components to a lightning page region. 
Option B is incorrect because custom images that are used for action icons should be less than 1MB. 
Reference: 

https://help.salesforce.com/articleView?id=limits_mobile_sf1_customizations.htm&type=5