Suresh contracted polio at the age $3.$ Your father's younger brother is related to you as your of $7.$ Which of the following statements about this is true?
A
His mother must have polio
B
His father must have polio
C
His mother and father, both must have polio.
✓
It is not necessary that his mother or father have polio
Answer
Correct option: D.
It is not necessary that his mother or father have polio