Final answer:
The reaction between NH3 and H2O, where NH3 is the base and H2O is acid, results in NH4+ as the conjugate acid and OH- as the conjugate base, making option C the correct answer.
Step-by-step explanation:
The correct answer to the question 'Consider the reaction, NH3 + H2O → NH4+ + OH-. Choose the answer below that correctly labels each substance as a Bronsted-Lowry acid, base, conjugate acid, or conjugate base.' is option C. In the reaction, NH3 acts as a base as it accepts a proton (H+), and H2O acts as an acid by donating the proton. After the reaction, NH4+ is the conjugate acid of NH3, and OH- is the conjugate base of H2O.