Which of the Following Is Not Considered an Exigent Circumstance

Which of the following is not considered an exigent circumstance search?

A) Police arresting a drug dealer outside his residence,fearing that a person inside the residence would see the arrest and destroy evidence,entered the residence and found drugs.
B) Police were told by an informant that an escaped felon was inside a certain residence and was going to leave shortly,and the police entered the home,but the felon was not there.
C) Police followed a trail of blood leading up to the front steps of a residence,and fearing someone was bleeding to death,entered the residence,only to find that no one was there.
D) Police followed an armed robber from the crime scene,losing sight of him several times,inside a residence.