The suggested answer is A.
Only the built DLL file is placed in the IBM Datacap installation directories. Do not place the RRX file in the Datacap installation directories; the RRX file is already imbedded within the DLL.
Procedure -
To deploy custom actions:
1. Choose one of the following routes:
To make the custom actions visible to a single application, place the DLL in the RULES directory of that application. For example, if you take this route, instead of placing the DLL in Datacap\dcshared\NET folder, you must place dcsmart.dll and irrx.dll into the Rules folder as well.
To make the custom actions visible to all applications, place the DLL in the RRS directory. The default location is C:\RRS.
2. Do not register the DLL.
References:
https://developer.ibm.com/answers/questions/364945/how-to-deploy-custom-actions/