Which of the following is true regarding pathogens?

The pathogens after entering into the body of the host multiples and interferes with normal vital  activities, resulting in morphological and  functional damage.

Pathogens can enter the body of the host through different ways. They can enter through blood, oral cavity, etc.

In severe cases of pneumonia, the lips and finger nails turn gray to bluish colour.

Rhino viruses only infect upper respiratory tract (nose and respiratory pathway) and not lungs.