Let $A=\{\emptyset,\{\emptyset\},\{\{\emptyset\}\}\}$.
(a) Determine which of the following are elements of $A: \emptyset,\{\emptyset\},\{\emptyset,\{\emptyset\}\}$.
(b) Determine $|A|$.
(c) Determine which of the following are subsets of $A: \emptyset,\{\emptyset\},\{\emptyset,\{\emptyset\}\}$. For (d)-(i), determine the indicated sets.
(d) $\emptyset \cap A$
(e) $\{\emptyset\} \cap A$
(f) $\{\emptyset,\{\emptyset\}\} \cap A$
(g) $\emptyset \cup A$
(h) $\{\emptyset\} \cup A$
(i) $\{\emptyset,\{\emptyset\}\} \cup A$.