A Capacitor Has a Voltage Of $391 \mathrm {~V}$ Applied Across Its Plates, and Then the Voltage Source Is

Multiple Choice

A capacitor has a voltage of $391 \mathrm {~V}$ applied across its plates, and then the voltage source is removed. What is the potential difference across its plates if the space between them is then filled with mica, having a dielectric constant of $5.4$ ?

A) $2110 \mathrm {~V}$
B) $18,675 \mathrm {~V}$
C) $72 \mathrm {~V}$
D) $641 \mathrm {~V}$