6. Consider the following JavaScript skeletal program // The main program var X function subl () var X,i function sub2 ) function sub3 ) Assume that the execution of this program is in the following unit order: main calls subl subl calls sub2 sub2 calls sub3 Assuming static scoping, in the following, which dec- a. laration of x is the correct one for a reference to x? i. subl ii. sub2 iii. sub3 Repeat part a, but assume dynamic scoping b