I think if the company is posing an interview question that requires total fluency over a legacy version of C++, they're probably not looking for graduates.
I tend to default to C++11 with C++[11,23]-portability.
In general, write maximally portable code without using vendor- or standard-specific features without a/some very good reason(s).
Also, C++11 is a monumental improvement over C++ from the days of rusty sharp edges of 90's C++ where one needed to follow strict standards to avoid nonobvious UB.