Place the Following Conditions in Order from the Least Difficulty

Multiple Choice

Place the following conditions in order from the least difficulty to the most difficulty in terms of the ability to learn language.

A) Williams syndrome,mutation in FOXP-2 gene,Down syndrome
B) mutation in FOXP-2 gene,Down syndrome,Williams syndrome
C) Williams syndrome,Down syndrome,mutation in FOXP-2 gene
D) Down syndrome,mutation in FOXP-2 gene,William syndrome