the arrowheads on the line means the line keeps on going and going like the Energizer Bunny and going to infinity, so the domain or extent horizontally will be
<h3>from -∞ to +∞ or ( -∞ , +∞ ).</h3>
Percentage is a value by a fraction of 100.
120 marks is equivalent to 60%
this means from the whole amount, 60 % of the whole amount is 120 marks
we need to find the full marks
if 60 % --- 120
then 1 % ---

full marks are 100 %
therefore 100 % -

100 % --- 200 marks
full marks are 200 marks
3.70 and 3.700 are some examples to get you started.
I think it’s the answer is D