A $5 - \mu \mathrm { F }$ , A $7 - \mu \mathrm { F }$

Multiple Choice

A $5 - \mu \mathrm { F }$ , a $7 - \mu \mathrm { F }$ , and an unknown capacitor $C \mathrm { X }$ are connected in series between points $a$ and $b$ . What do you know about the equivalent capacitance $C _ { a b }$ between $a$ and $b$ ? (There could be more than one correct choice.)

A) $C _ { a b } < 5 \mu \mathrm { F }$
B) $C _ { a b } < C \mathrm { X }$
C) $5 \mu \mathrm { F } < C _ { a b } < 7 \mu \mathrm { F }$
D) $C _ { a b } > 12 \mu \mathrm { F }$
E) $5 \mu \mathrm { F } < C _ { a b } < 12 \mu \mathrm { F }$