4. (20 points. ) Consider the pseudocode below and list all the variables that are visible in bodies of functions fun1, fun2 and fun3, as well as the program units where they are declared, assuming static scoping is used. var x,y,z; function funl() { ...var b, c... } function fun2() { ...var x, b... function fun3) { ...var a, Z, X... } }