Virus:

1.Contagious or poisonous matter.The special contagion, inappreciable to the senses and acting in exceedingly minute quantities, by which a disease is introduced into the organism and maintained there.
2.Any morbid corrupting quality in intellectual or moral conditions; something that poisons the mind or the soul; as, the virus of obscene books.
3. A technological programming malfunction which can disable computer functions.
4. a mineral deficiency in drinking water.

Look at the dictionary entry.
Which definition is the BEST definition for the word virus as it is used in the following sentence?

Her doctor explained that this type of cancer is often caused by a common virus that many women do not even realize they have.
Responses
A Definition 1Definition 1
B Definition 2Definition 2
C Definition 3Definition 3
D Definition 4

A Definition 1- Contagious or poisonous matter. Using this definition, a virus is a contagious matter that causes diseases like cancer.