Answer: d) 24
Explanation:
This is because the astronomical start of summer for the southern hemisphere is generally marked on December 21st. During this season the days are longer than the nights, and as we get closer to the South Pole ( as McMurdo, Antarctica is), we will have up to 24 hours of sunlight.
That is why from December 21st, the sun is visible for 24 hours and the next days (the closer it is to the north pole) it will stay that way. Therefore, the inhabitants of this area can enjoy sunlight for a longer period.