How do you supply the default value for that configuration option?

In a custom module you are adding a new field to the store configuration. The field will set the value for the configuration path mycompany/mymodule/myoption.

How do you supply the default value for that configuration option?
A . In the config/default/mycompany/mymodule/myoption node in the etc/config.xml file
B . In the system/mycompany/group/mymodule/field/myoption node in the etc/system.xml file
C . In the menu/default/section/group/field node in the file etc/adminhtml/menu.xml
D . In the system/section/group/field/value node in the etc/adminhtml/system.xml file

Answer: A

Explanation:

https://magento.stackexchange.com/questions/173286/magento2-how-to-create-admin-page-with-configuration-fields