There should be an option for "C was my first programming language and I used it exclusively for years - many years ago".
It seems like this could be either the second or third option, depending on how well you still know it. Perhaps the second if you still know it well and the third if you've gotten really rusty in it. I can add the option if this doesn't make sense in your case.
It's similar to offering 3 options for Marital Status: Single, Married or Divorced. It's impossible to interpret the results in any meaningful way (Divorced and single? Divorced and remarried? Is it important that I've ever been divorced? Or do you just want to know if I'm currently married or not?). It's better to separate these questions.