Answer :
A pathogen that lives on mucous membranes but does not survive very long in the outside environment is most likely transferred from one host to another by (a) direct transmission
Most likely, direct transmission occurs when a pathogen that thrives on mucosal membranes but is short-lived in the external environment moves from one host to another.
This form of transmission occurs through physical contact, where the infectious agent is transferred by actions such as touching, kissing, sexual intercourse, or droplet sprays from one person to another.
Since mucous membranes are involved in this scenario, the pathogen requires contact with these membranes to enter the body. A typical example includes transferring the pathogen from the hand to the mouth or eye.
This is opposed to indirect transmission, which involves inanimate objects, known as fomites, which become contaminated with pathogens. Indirect transmission occurs when a susceptible host later touches the fomite and transfers the contaminated material to a portal of entry, such as the mouth or nose.
Therefore, (a) direct transmission is the correct option.