The first and second lines of defense against microbial invasion are part of The first and second lines of defense against microbial invasion are part of microbial antagonism. innate immunity. species resistance. species immunity. adaptive immunity.

the correct option is B: "innate immunity"

Explanation:

The first line of defense comprises the skin, secretions of skin and mucous membranes. These structures are responsible for preventing entry of foreign particles that may cause harm.

The second line of defense consists of an inflammatory response, developing a fever, leukocytes and non-specific antimicrobial proteins.

If the body's first line of defense fails to keep out the pathogen, the second line of defense kicks in to defend the body.

And now the third line of defense, also called 'adaptive immunity', antibodies, lymphocytes and memory cells. These respond in a specific manner to the microbe that has invaded the body.

Hope that answers the question, have a great day!