Answer:
b=5..............is the answer
Take a look at the function

. You can simplify it to

. If x=0, then y=2 and when y=0, x=3. You obtain two points (0,2) and (3,0) that lie on the line

.
Since

, the line

should belong to the shaded area.
Now take point (0,0). Since

, you can conclude that point (0,0) belongs to the shaded area.Using all these thoughts, you can make a conclusion that the correct choice is B.
Supplementary angle = Angels which add up to 180 degrees
Angle CED
She used 0 other flowers for the arrangements it says in the question "Morita used 10 daisies to make arrangements" it didn't say she used anything else