Which of the following statements is logically equivalent to "If you live in a mansion, then you have a big heating bill."? If you do not live in a mansion, then you do not have a big heating bill. If...

If you do not live in a mansion, then you do not have a big heating bill.

If you have a big heating bill, then you live in a mansion.

If you live in a mansion, then you do not have a big heating bill.

If you do not have a big heating bill, then you do not live in a mansion.