Consider the pairs of ethers A through F as shown below. To the right of each pairs is a description of reaction conditions to be applied to each. One compound of the pair will react more rapidly than the other. Find out the number of reactions in which the first ether more rapidly cleaved than the second ether.

Ether pairs		Conditions
A.		Treated with $\mathrm{HBr}$ in ${\mathrm{CH}}_3-\mathrm{CN},40°\mathrm{C}$
B.		Treated with ${\mathrm{H}}_2{\mathrm{SO}}_4$ in ${\mathrm{CH}}_3\mathrm{CN},40°\mathrm{C}$
C.		Treated with ${\mathrm{H}}_2{\mathrm{SO}}_4$ in ${\mathrm{CH}}_3\mathrm{CN},40°\mathrm{C}$
D.		Treated with $5\%$ aqueous ${\mathrm{H}}_2{\mathrm{SO}}_4,25°\mathrm{C}$
E.		Treated with $5\%$ aqueous ${\mathrm{H}}_2{\mathrm{SO}}_4,25°$
F.		Treated with ${\mathrm{H}}^{\oplus }/{\mathrm{H}}_2\mathrm{O}$