Answer:
A) involves changes in temperature
Explanation:
The figure is missing, but I assume that the region marked X represents the region in common between Gay-Lussac's law and Charle's Law.
Gay-Lussac's law states that:
"For an ideal gas kept at constant volume, the pressure of the gas is directly proportional to its absolute temperature"
Mathematically, it can be written as

where p is the pressure of the gas and T its absolute temperature.
Charle's Law states that:
"For an ideal gas kept at constant pressure, the volume of the gas is directly proportional to its absolute temperature"
Mathematically, it can be written as

where V is the volume of the gas and T its absolute temperature.
By looking at the two descriptions of the law, we see immediately that the property that they have in common is
A) involves changes in temperature
Since the temperature is NOT kept constant in the two laws.
Point f because that is when it starts going down
Answer:
13.2 g Na2CO3
Explanation:
Convert 10.0 g NaOH to mol.
10.0 g x 1 mol/39.997 g = 0.250 mol
Use mol ration given by the equation: 2 mol NaOH to 1 mol Na2CO3
0.250 mol NaOH x 1 mol Na2CO3/2 mol NaOH = 0.125 mol Na2CO3
Finally, convert the moles of Na2CO3 to grams.
0.125 mol Na2CO3 x 105.99 g/1 mol = 13.2 g