Why is it that during changing weather,one is advised to avoid closed,crowded,and air-conditioned places like cinema halls?

• A
  To prevent exposure to high levels of carbon dioxide.
• B
  To avoid the spread of infectious agents that thrive in moist conditions and to protect individuals whose immune systems are stressed by environmental adaptation.
• C
  Because air-conditioned places have low oxygen levels.
• D
  To avoid the noise pollution in cinema halls.