Not my wording. The correct answer is not "No foul".
3/7 @ A-43. A32 carries the ball into the side zone, trying to cut up field. B90 grabs A32 inside the shoulder pads at the A-47 and begins to try to abruptly pull the runner to the ground. A32 is able to advance forward while B90 continues to pull A32 downwards at the shoulder pads. A32’s knee finally hits the ground at the A-49.
Ruling:
This is a horribly, horribly written question. What does, "...beings to TRY to abruptly pull the runner to the ground..." mean? Try? Is that anywhere in the rule? Does he, or doesn't he abruptly pull him down? In a written question, you can NOT expect people to use judgment. If we can't see something that must be seen, hear something that must be heard, taste something that must be tasted, smell something that must be smelled, or feel something that must be felt, we simply can't make a judgment (ruling). Give me a video, and I'll give you an answer. Otherwise, give me a written description that has enough information to lead me to the correct answer.
It seems as though they were trying to lead you to the conclusion that there was, in fact, no 'abrupt' pull-down. OK, so write it like this:
3/7, A-43. Ball carrier A32 is advancing at the A-45 when B90 grabs A32 at the collar of A32's shoulder pads. A32 is able to continue his advance while B90 maintains his firm grip on A32 at the collar of the shoulder pads, pulling steadily downwards. The ball is above the A-49 when A32’s knee contacts the ground, inbounds.
Ruling: A, 4/1, A-49, ready when spotted (40 and running). No foul for a horse-collar tackle, because there was no 'abrupt' pull-down.
I get to the same point, with full clarity, with approximately 2 fewer characters.