Answer:
c
Explanation:
The formula for y=3x^2+6x+2 is y=ax^2+bx+c. And knowing the purpose of each variable will help you greatly:
a: which way the parabola opens (a<0 is down, a>0 is up)
b: moves the graph up or down
c: the y-intercept
In other graphs (like slope-intercept form, etc.), we know that the y-intercept doesn't change, or is the most constant.