Best language
As a "C" programmer for more than 20 years, I have to agree with "C" as the choice, but that's not necessarily the best answer.
I'm a manager of a group of software engineers and I do quite a bit of hiring. My suggestion is that you learn to apply the basics (algorithms, data structures, etc) to different languages. It's rare that I find someone that can do exactly what I need them to do -- I look for people that have broad knowledge and can THINK. The people that tend to do the best in my department are the ones that can apply what they know to different situations that they haven't seen before.
So, yes, "C" is a good answer, but if you can't apply what you learn with "C", then you won't be that useful.
Brad