I think Letter 'D' is the answer.
#KEEP_ON_LEARNING
>Brainliest and follow<
what is a sign that a person had swallowed a poisonous substance?
A. Sleepy
B. Turning Blue
C. Pain or a burning sensation
D. All of the above
#CarryOnLearning
#FollowForThankYou
--Krysha