Which line represents the axis of symmetry? A) 
y = 0

B) 
x = 2

C) 
x = 3

D) 
y = –1

C.

x=3

Notice how the line is reflected at a vertical line (not shown) at (3, 0)

Therefore x=3 since that is the line where the reflection occurs.

Step-by-step explanation:

a. 12.5 kg

step-by-step explanation:

f = ma

so

m = f/a = (2500 n)/(200 m/s²) = 12.5 kg

1 n = 1 kg·m/s²