The ZCD_NV_STARTUP_OPTION is a 1 byte config parameter, config id is 0x0003 , This is a parameter which is to written in the NV memory with the ID & values as needed.
the definition is in ZComDef.h as #define ZCD_NV_STARTUP_OPTION 0x0003
for more information please refer to "Z-stact Simple Api.pdf" in the folder C:\Texas Instruments\ZStack-CC2530-2.5.1a\Documents
Regards
Biprangshu Saha