In the winter, under certain conditions related to water vapor
pressure in the air, snow will sublime. Which of the following
describes the entropy change during the sublimation?
a. increases
b. varies at random
c. remains the same

Hi teatea!
The correct answer is (a): the entropy increases as snow becomes water
vapor (that is, as snow sublimes, or as water goes from solid to
gaseous state).

"Entropy is a measure of the randomness or disorder of a substance.
The entropy of a solid is less than of a liquid is less than of a gas.
As the temperature increases, the substance becomes more disordered,
its entropy increases."

Science Foundations
http://216.239.37.104/search?q=cache:54HwHvVe8xMJ:www.chem.usyd.edu.au/~mjtj/EDUF1014/EDUF1014.topics/Topic6.html+%22entropy+change%22+sublimation+water&hl=en&ie=UTF-8


Google search strategy 
"entropy change" sublimation water
://www.google.com/search?sourceid=navclient&ie=UTF-8&oe=UTF-8&q=%22entropy+change%22+sublimation+water
 
 
I hope this helps! If you have any doubt regarding this answer, please
don't hesitate to request a clarification.
 
 
Best wishes! 
elmarto