Heat is simply another word for? a. all the above b. temperature c. thermal energy that flows from hot to cold d. thermal energy

'Heat' is another term to describe thermal energy, whether the thermal energy
just sits in some object or substance, or flows from one object to another one
that's cooler.

'Heat' is NOT another word for 'Temperature'.  If you think of it that way,
then you'll have a hard time UNlearning that idea and getting yourself
unmuddled and straightened out.  Please don't even go there.