A second-order linear time-invariant system is described by the following state equations\(\frac{{\rm{d}}}{{{\rm{dt}}}}{{\rm{x}}_1}\left( {\rm{t}} \right) + 2{{\rm{x}}_1}\left( {\rm{t}} \right) = 3{\rm{u}}\left( {\rm{t}} \right)\)\( \frac{{\rm{d}}}{{{\rm{dt}}}}{{\rm{x}}_2}\left( {\rm{t}} \right) + {{\rm{x}}_2}\left( {\rm{t}} \right) = {\rm{u}}\left( {\rm{t}} \right) \)where x1(t) and x2(t) are the two-state variables and u(t) denotes the input. If the output c(t) = x1(t), then the system is:

• A. controllable but not observable
• B. observable but not controllable
• C. both controllable and observable
• D. neither controllable nor observable