a discrete graph (I had to look this one up)
You can start from any of the options mentioned above however make sure to follow the rule of BODMMAS but you can start from (D) 54÷3 if you just really want a section to start with
QUESTION :-
what is the value of x to the nearest whole number?
ANSWER :-

SO
the nearest whole number-->
20.7 --> approximately --> 21 units