(lots of points) (dumb answers will be reported)
which best explains whether or not triangles rst and acb are congruent?

By doing a reflection over the x-axis and a translation two units to the left (Choice 1), we see that triangle RST is congruent to triangle ACB.

Let's test this.

R(1,1)
S(1,5)
T(4,1)
A reflection across the x-axis follows the rule of (x,-y). Doing this, we get the new points:
R(1,-1)
S(1,-5)
T(4,-1)

Then we move the triangle two units to the right. This follows the rule (x-2,y). Our new points are:
R(-1,-1)
S(-1,-5)
T(2,-1)
We can see that points R, S, and T correspond to all the points on ACB, so this answer choice is correct.

:)