The life-threatening disease epiglottitis can be prevented by which immunization?

Correct Answer: B

Rationale: Hib vaccine prevents *Haemophilus influenzae* type b infections, including epiglottitis, a life-threatening airway obstruction. MMR, HepB, and polio vaccines target unrelated diseases (measles/mumps/rubella, hepatitis B, poliomyelitis), none of which cause epiglottitis.

Correct Answer: D

Rationale: Absolute contraindications to DTaP include a prior anaphylactic reaction (Choice B) due to risk of recurrence, and encephalopathy within 7 days of a prior dose without another cause (Choice C), per CDC, as these indicate severe risk. Moderate/serious illness (Choice A) is a precaution, not an absolute bar—vaccination is delayed until recovery. Choice D (B or C) captures both contraindications.

Correct Answer: B

Rationale: Preschoolers (3-5 years) are in Erikson’s Initiative vs. Guilt stage, exploring purpose. Trust vs. Mistrust (infancy), Identity vs. Role Confusion (adolescence), and Industry vs. Inferiority (school-age) don’t apply.

Correct Answer: B

Rationale: Poisoning is listed as the leading cause under 1 year in the document, though falls are more common per CDC (<1 year data). Assuming context (e.g., post-infancy), Choice B aligns with the answer provided.

Correct Answer: B

Rationale: Difficulty concentrating is a hallmark of ADHD (DSM-5). Other choices are unrelated symptoms.