Which code segment should you add at line 03?

You are developing an ASP.NET Web application.
The application includes a Icomparer<string> implementation named CaseInsensitiveComparer that compares
strings without case sensitivity
You add the following method.(Line numbers are included for reference only.)
01 public IEnumerable<string>SortWords(string[] words)
02 {
03
04 }
You need to sort the array by word length and then by alphabetic order, ignoring case.
Which code segment should you add at line 03?

A.
return words.Orderby(a => a, new CaseInsensitiveComparer()).ThenBy(a =>a.Length);

B.
return words.Orderby(a =>a.Length).Orderby(a => a,new CaseInSensitiveComparer());

C.
return words.Orderby(a =>a.Length).ThenBy(a=> a, new CaseInSensitiveComparer());

D.
return words.Orderby(a =>a.Length.toString(), newCaseInSensitiveComparer());