Answer:
B
Step-by-step explanation:
A is incorrect as you are not directing that to the person. you are only blatantly mentioning it.
B is correct because you are stating it to another person and using the second person correctly.
C is incorrect since the pronoun used here is "we", which I doubt a 911 operator would say unless he was also in a crisis.
D is incorrect because the pronoun used in the conjugation is "I", which also makes no sense.
Espero que esto sea de ayuda :)