What is an activity the customer or partner is responsible for in RISE with SAP S/4HANA Cloud, private edition?

What is an activity the customer or partner is responsible for in RISE with SAP S/4HANA Cloud, private edition?
A . Implementation of SAP Best Practices
B . Initial Setup of SAP Fiori launchpad
C . Implementation of technical release upgrades
D . Customization of business processes

Answer: D