Answer:
The correct answer is - 1/2
Step-by-step explanation:
the ability to roll the tongue is dominant over those who can not roll the tongue. The man is Rr (man), heterozygous. The woman is recessive and can not roll
Rr (man) x rr (woman)---Parents
r
R Rr (roll)
r rr (cann't roll)
The probability of their children to able to roll = 1/2 = 50%