A down-and-out put has barrier $20 and strike $30. The put expires after four time steps when the underlying is expected to have values $50, $40, $28, $22 or $18. What are the possible values of the put at expiry?

Group of answer choices

$0, $10 ot $20.

$0, $2 or $8

$0 or $12.

$0, $2, $8 or $12.