Answer Happy

Fido and Spot are dogs. Assume whenever it is hot, Fido and Spot
are lazy and quiet. Based on this assumption, which statement must
be true?
If it is hot, Fido is lazy and Spot is
quiet.
If Fido is quiet or Spot is lazy, it is
hot.
If it is not hot, Fido and Spot are neither lazy nor
quiet.
If Spot is lazy but Fido is not quiet, it is not
hot