Final answer:
The rule is that pasta doubles in size and requires 4 quarts of water per pound to cook properly. 1 quart equals 4 cups, matching the standard cooking recommendation.
Step-by-step explanation:
The rule of thumb for pasta is that it doubles in size as it cooks, and you need to use 4 quarts of liquid to cook 1 pound of pasta. Hence, the correct answer would be option (a) Doubles, 1 quart. This is because 1 quart is equivalent to 4 cups, and the standard recommendation is to use at least 4 cups of water for every pound of pasta. It's important to note that 1 gallon equals 4 quarts, so 4 quarts of water is also equal to 1 gallon, which is sufficient for cooking a pound of pasta.
When cooking pasta, most people add a small amount of salt to the water, usually a pinch or about one-fourth of a teaspoon, mainly for flavor enhancement rather than significantly raising the boiling point of the water. Adding a cup of salt, which is close to 1 pound, would raise the boiling point by about 1°C, but this is not a common practice in cooking pasta.