Select all valid sets.

Question $6$Answer

a$.$

$\{"$alpha$",$ "bravo", "charlie"$\}$

b$.$

$\{4,2,23,66,23\}$

c$.$

$\{1,1\mathrm{.}5,2,2\mathrm{.}5,3\}$

d$.$

$\{\}$

e$.$

$\{(1,2),(3,4),(5,6)\}$

f$.$

$\{[$False$,$ True$],[$True$,$ True$],[$True$,$ False$],[$False$,$ False$]\}$