B. I think correct answer
The answer would be "Father's father" 'cause when boy born, he receives Y chromosome from his father and not X so he can't transfer it to his daughter, as he will transfer his X chromosome to her.
In short, Your Answer would be Option D
Hope this helps!
I would select B or C as the answer because i have no idea what the other ones are :)
Answer: 30 years
Explanation: what is 30 plus 30... 60 it says he died in 1930 and discoverd the thing in 1960 add 30 boom its been 30 years
