12. A 2.0 kg block on a frictionless table is connected to two ideal massless springs with spring constants k1 and k2 whose opposite ends are fixed to walls, as shown in the figure. What is the angular frequency of the oscillation if k1=7.6 Nm and k2=5.0 N/m?(A) 2.5 rad/s (B) 3.5 rad/s (C) 0.40 rad/s (D) 0.56 rad/s(E) 5.5 rad/s.