Final answer:
The stack with all activation record instances, including static and dynamic chains, when execution reaches position 1 in the given skeletal program.
Step-by-step explanation:
When execution reaches position 1 in the given skeletal program, the stack would consist of the following activation record instances:
- bigsub() at level 1
- a() at level 2
- b() at level 3
The static chain would connect bigsub() to a(), and the dynamic chain would connect a() to b().
Static chains are used to link functions that are in a higher level in the call stack to functions at a lower level. Dynamic chains, on the other hand, connect function calls that are made within the same level of the call stack.