Which of the Following Options May Be Available to a Lessee

Which of the following options may be available to a lessee against whom an acceleration clause in a lease has been triggered?

A) The validity of the clause may be challenged in court on the basis of non est factum
B) The validity of the clause may be challenged on the basis that it is inequitable
C) The validity of the clause may be challenged on the basis that it is a penalty
D) The validity of the clause may be challenged in court on the basis of mistake
E) The validity of the clause cannot be challenged.