For each of the halides listed, choose one of the following four general synthetic routes as the most appropriate (workable yet simple) method of synthesis of the anhydrous halide: Method 1, anhydrous salt results from evaporating the reaction mixture of the metal hydroxide plus the hydrohalic acid; Method 2, the salt precipitates in anhydrous form upon mixing solutions containing the cation and the anion; Method 3, the hydrated halide can be dehydrated by an appropriate chemical dehydrating agent; Method 4 , a strictly anhydrous method of synthesis (halogen exchange or redox) is required. Halides: a. $\mathrm{CF}_4$;
b. AgI;
c. KF;
d. $\mathrm{SiCl}_4$;
e. $\mathrm{BiCl}_3$;
f. $\mathrm{SiI}_4$ :
g. AuI;
h. $\mathrm{RbBr}$;
i. $\mathrm{NiCl}_2$;
j. $\mathrm{BiBr}_3$;
k. $\mathrm{LaF}_3$;
I. $\mathrm{SnCl}_2$;
m. $\mathrm{PrCl}_3$ :
n. $\mathrm{WF}_6$.