A recent study has proved that children are more capable at picking up languages than are adults, from their mother tongue to even foreign ones, and remembering them lifelong.
A. children are more capable at picking up languages than are adults, "from their mother tongue to even foreign ones" refers to languages and not the "adults" or their "ability"-
wrong!
B. children are more capable at picking up languages than adults,
children are more capable at picking up languages than they are capable of picking up adults???--- see the comparison error??!-
wrong!!C. children are more capable than adults at picking up languages,
Correct! as we are comparing the capability of children with the capability of adults!-
correct!D.
children, more capable than adults at picking up languages,
children are not from their mother tongue!!- meaning error-
wrong!!E. children pick up languages more capably than adults,
children pick up languages more capable than they pickup adults??--- Comparison error-
wrong!