6. For the following JavaScript skeletal program, assume main calls fun1, fun1 calls fun3 (in line 2) and fun3 calls fun2; //the main progranm var v, ys function fun1)0 var x, z; function fun20t var z //Line 1 .//Line2 function fun3)0 var y; //Line 3 a. List all variables, along with the functions in which they are declared, that are visible at Line 1 in the program. b. Repeat part (a), but list the variables that are visible at Line 3