D. Holding your nose
Your sense of smell is a big part of your taste, which is why it helps to plug your nose when eating something bad.
The correct answer for question number 1 is A - eukaryotes are the name
for unicellular organisms that dominated earth up to the Precambrian
times.
The correct answer for question number 2 is C - the
greenhouse effect is related to the phenomenon of an increase in average
surface temperature known as global warming.
The correct
answer for question number 3 is D - the colourless and odourless gas
that is produced by the radioactive decay of Uranium-238 and is considered
to be a cancer-causing agent is Radon.
The correct answer for
question number 4 is B - Scientists can determine if oxygen existed in
Earth's Archean atmosphere by looking for oxidized iron in rocks.
B is the best answer I hope it help
