Some humans are able to roll their tongue, while others are not. Two parents (both tongue-rollers) have four children, all of whom are not tongue-rollers. Which of the following statements hold true regarding this?
(i) The allele for tongue-rolling is dominant.
(ii) The probability that their next child will be a tongue-roller is 0.5.
(iii) The probability that their next child will not be a tongue roller is 0.75.
(iv) Both parents have one allele for tongue-rolling and one allele for non-tongue-rolling.

Options

A. (i) and (iii) only
B. (i) and (iv) only
C. (ii) and (iii) only
D. (ii) and (iv) only

Answer

B