Answer:
C
Step-by-step explanation:
Because its a cost vs minutes graph, and it starts at (0,2) and goes to (1,5)
x=
Q= illumination
I = intensity
Q= I/d^2
Q_total =
=
now Q' = 0
⇒I
[/tex]
is the required point
9.9433e+13
Mark me brainliest