Q $28(4$ pts$)$ in Fig $1,$ assuming the program starts executing in MAIN and then calls F$2,$ which then calls F$1$ which then calls F$3$ that then calls F$4.$ Using DYNAMIC Scoping, what is the referencing environment if in F$4?$

a$)\{$Global :$($X and A and B$),$ F$1$:W$,$ F$4$:B$\}$

b$)\{$MAIN: X$,$ F$1$:W$,$ F$3$:A$,$ F$4$:B$\}$

c$)\{$Global :A $,$ MAIN: X$,$ F$1$:W$,$ F$4$:B$\}$

d$)\{$Global :$($X and A$),$ F$1$:W$,$ F$4$:B$\}$

e$)$ Can$$t tell by looking at fig $1.$