A. Is the answer because a coefficient is the number that is attached to a variable or in front of it. There cannot be a parenthesis in between them like in letter D. So your answer is letter A because the 3 in 3y+1 is a coefficient. Hope this helps!
Guests at an amusement park must be at least 54 inches tall to be able to ride the roller coaster. which graph represents the set of heights that satisfy this requirement?