A、One should prop his head with his elbows on the table. B、One should hold an extra napkin. C、One should be upright in his chair

In my childhood home, dinner was enjoyed with hushed voices, and the topics open for discussion were very much restricted. We were not allowed to bring up anything that was potentially unappetizing; body functions, bugs, murder and mayhem in general were all strictly forbidden topics. If I had to leave the table to use the toilet, I had to verbally excuse myself without mentioning what it was that I was going to do. "May I be excused, please? I need to wash my hands." I would say. My mother would say, "Sure." My father would often play a joke on us by saying, "Your hands don’t look dirty to me!"
    As for eating, we did it quietly. No eating noises were allowed. Everything must be done as quietly as possible. Therefore, we had to eat with our mouths closed. To make a "smacking" noise was, perhaps, the worst offense possible. While drinking soup or coffee or wine "slurping" was also forbidden. If any sound whatever was created by our intake of food or beverage, it constituted bad manners! With that in mind, it was, of course, unthinkable to speak with one’s mouth full of food, so speaking only occurred before or after one had taken in food and swallowed it.
    How one sits at the table is also prescribed. One is to sit up straight with the recessive hand in one’s lap holding a napkin while the dominant hand holds the fork or spoon. The only time one is allowed to have both hands on the table is when one is using a knife to cut something, but as soon as the cutting is done, the recessive hand goes back to the lap. Also, elbows are not allowed on the table. Therefore, one props the arm against the edge of the table just below the elbow. One should never reach for any food on the table; one should ask someone sitting near it to give it to you.  "Would you please pass the potatoes?  ....  May I trouble you for the salt?" These are phrases that you are likely to hear on any given night of the week at a family dinner.