[peripetylabs]

There exist proof and verification tools for C, like ACSL and Frama-C, [1] or LCL and Splint. [2,3] Not to mention the myriad of static and dynamic analysis tools. You can prove that a piece of C code does or doesn't contain certain bugs -- this is not the case for higher-level languages (except perhaps Haskell and ML). That is why C is used for highly sensitive projects like avionics.

I would say: learn C and high-level languages.

[1] http://frama-c.com/acsl.html

[2] www.hpl.hp.com/techreports/Compaq-DEC/SRC-RR-74.pdf

[3] http://splint.org/