The product of a Lewis acid-base reaction is a(n) , a single species that contains a new covalent bond. The Lewis acid-base definition focuses on the donation or acceptance of an electron pair to form a new covalent bond in an adduct, the product of an acid-base reaction. Lewis bases the electron pair, and Lewis acids it.

Adduct, donate, accept

Explanation:

Lewis acids are those having suitable vacant orbital for electron acceptance and forming a covalent bond with an electron rich species. Example: (B has vacant 2p orbital for electron acceptance)

Lewis bases are those having energetically available unshared electrons that can be donated to an electron deficient species and form a covalent bond. Example: (N has energetically available lone pair)

So, product of Lewis acid-base reaction is an adduct () where a new covalent bond is formed between B and N.

i'm pretty sure its b i might be wrong though!