The correct answer would be b. However they are also all numbered. But the correct answer is B Chemical Symbols.
Answer : The change in entropy is 
Explanation :
Formula used :

where,
= change in entropy = ?
m = mass of water = 1.00 kg
= heat of vaporization of water = 
T = temperature = 
Now put all the given values in the above formula, we get:


Therefore, the change in entropy is 
It will be great if you searched on the internet then just questioning it on here because on here it takes a bit to get that so might as well google it
The systematic name of Mg(NO3)2 is magnesium nitrate. If you were confused, there are two of the nitrate because magnesium has a charge of 2+ while just one nitrate has a 1- charge. They would have to cancel out because it is an ionic compound.