Show the stack with all activation record instances, including static and dynamic chains, when execution reaches position 1 in the following skeletal program. Assume bigsub is at level 1. function bigsub() { var mysum; function a() { var x; function b (sum) { var y, Z; ... c(z); } // end of b b(x); } // end of a function c(plums) { ... <------ } // end of c var l; a(); } // end of bigsub