In the given graph, the two lines intersects at

And intersection point is that point , where the y values of the two graphs are equal .
That is

And at x=-2, the y values are equal. THat is

So the correct option is D.
Changing the 30 to 10 is a 20 unit drop ( 30-10=20)
so the line would shift vertically down by 20
<span>The line will shift vertically down by $20.</span>
So,
To get how many wingbeats per minute,
200x60=12000 because there are 60 seconds in a minute
To get how many in 3 minutes,
12000x3=36000
Hope I helped!