Why Is Diagnosis of an Infection More Difficult in Elders

Why is diagnosis of an infection more difficult in elders than other age groups?

A) important warning signs such as a fever may be atypical or absent
B) nonspecific symptoms such as confusion or fatigue accompany an infection
C) warning signs are misinterpreted as an association to age-related decline
D) elders often do not report warning signs to their physicians
E) all of the above