​Vaccinations may be less effective in protecting against infectious diseases among people who experience ________.

A) stress
B) ​many daily hassles
C) ​few daily hassles
D) ​exposure to cigarette smoke

Daily Hassles

Regular minor irritations or problems that, cumulatively, can have a significant impact on a person's mental health.

Infectious Diseases

Diseases caused by pathogens like bacteria, viruses, fungi, or parasites that can spread directly or indirectly from one person to another.