Answer:
D. Both A and B are situations that would cast doubt on this assumption
they are:
A. A teacher reports that after testing her class on the ability to roll their tongue, with very little effort the non-tongue-rollers can learn to also roll their tongues.
B. A student who can roll his tongue has a mother and father, both of whom cannot.
Explanation:
A traits is a special characteristics or qualities that is common to an organism. it is usually passed down/ inherited from parents to offspring or as a result of environmental factors. some traits that are inherited from parents cannot be inherited from the environment those are genetically inherited characteristics.
Tongue rolling is a simple genetic traits that is capacity of an individual to roll the lateral edges of the tongue upwards into a tube. it is inherited from one parent.
The option A and B contradicts as it is not a learn characteristics but an inherited trait. and student can only role his/her tongue if one of the parent has that special ability to role the tongue and if that trait was passed to that child. so a student cannot possess that ability to roll the tongue if their parents do not have it.
