Point $C$ is free to translate. What is the force in member $BC$ in this case? (by convention: positive indicates tension, negative indicates compression)

A. $-9.00$ $kN$
B. $-5.85$ $kN$
C. $-5.40$ $kN$
D. $0$ $kN$
E. $5.40$ $kN$
F. $5.85$ $kN$
G. $9.00$ $kN$