the type of hair their parents have the type of hair their brothers and sisters have their hair color their skin color
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Some people have straight hair and some have curly hair. What decides whether a person will be born with curly hair or straight hair?
Possibilities:
- the type of hair their parents have
- the type of hair their brothers and sisters have
- their hair color
- their skin color

the type of hair their parents have