<Tr> <Th> Aliases </Th> <Td> Straw Hat Luffy </Td> </Tr> <Tr> <Th> Relatives </Th> <Td> <Ul> <Li> Monkey D. Garp (grandfather) </Li> <Li> Monkey D. Dragon (father) </Li> <Li> Portgas D. Ace (adopted brother) </Li> <Li> Sabo (adopted brother) </Li> </Ul> </Td> </Tr> <Ul> <Li> Monkey D. Garp (grandfather) </Li> <Li> Monkey D. Dragon (father) </Li> <Li> Portgas D. Ace (adopted brother) </Li> <Li> Sabo (adopted brother) </Li> </Ul> <Li> Monkey D. Garp (grandfather) </Li>

What is the d in monkey d luffy