Does the set of ordered pairs {(5,13), (6,12), (7,11) (9,9) (10,11)} define a function? A: No, because 9 is paired with itself.
B: Yes, because each input has only one output.
C: No, because there is no ordered pair in the set where x = 8.
D: No, because 2 different x-values are paired with 11

I’ll mark brainlest!!

Andy wants to find the distance d across a river. he located points as shown in the figure, then use similar triangles to find that d = 223.5 feet. how can you tell without calculating that he must be wrong? tell what you think he did wrong and correct his error. round your answer to the nearest tenth if necessary. andy must have used the wrong . the distance d is actually feet.