Refer to the Following Formula

Multiple Choice

refer to the following formula:
∼(∀x) {(Ix • Jx) ⊃ [Kx ≡ (La • Lb) ]}
-Which of the following variables in the formula are free?

A) The x that follows the I.
B) The x that follows the J.
C) The x that follows the K.
D) All of the above.
E) None of the above.