Answer:
Scent and Taste work in conjunction because when your brain smells food, it pulls up a picture or memory of that food in your head, and you remember what it tasted like and if you enjoyed it.
Only some of the food. Salt does not really have a smell, so it does not do anything, but all the others do and are heightened
Explanation:
Take cotton candy for example. When you smell cotton candy, you smell SUGAR and lots of it. You know that sugar tastes good and as such you now want to eat the cotton candy.
For this example, we will use lemonade. Lemonade is commonly a drink that most love on a hot summer day at the beach. When you smell the lemonade, it reminds your brain of how good it tasted and pulls up the memory at the back of your mind, making you feel happy and relaxed. It then ends up tasting better
(This is my first answer, it won't be perfect)