Based on this excerpt from John Snow's "On the Mode of Communication of Cholera," what is the meaning of the word morbid?

Besides the facts above mentioned, which prove that cholera is communicated from person to person, there are others which show, first, that being present in the same room with a patient, and attending on him, do not necessarily expose a person to the morbid poison; and, secondly, that it is not always requisite that a person should be very near a cholera patient in order to take the disease, as the morbid matter producing it may be transmitted to a distance.

A.
benign
B.
precarious
C.
pestilent
D.
transmittable
E.
superfluous

Question

Based on this excerpt from John Snow's "On the Mode of Communication of Cholera," what is the meaning of the word morbid?

Besides the facts above mentioned, which prove that cholera is communicated from person to person, there are others which show, first, that being present in the same room with a patient, and attending on him, do not necessarily expose a person to the morbid poison; and, secondly, that it is not always requisite that a person should be very near a cholera patient in order to take the disease, as the morbid matter producing it may be transmitted to a distance.

A. 
benign
B. 
precarious
C. 
pestilent
D. 
transmittable
E. 
superfluous