Which of the following statement is not correct about the penal clause?

a.The court can declare the penal clause void, if the penal clause is contrary to law, moral, good customs, public order, and public policy.

b.If the principal obligation is void, the penal clause is likewise void.

c.As a rule, the creditor may enforce both the principal contract and penal clause at the same time.

d.Penal clause is just an accessory.