The recent era of large, ground-based abundance surveys has unraveled the chemical structures of our Milky Way galaxy. The most striking abundance feature is the alpha-abundance bimodality. The low-alpha stars are younger (1-8 Gyr) while the high-alpha stars are older (8-12 Gyr) and have a thicker distribution. There are a number of different models that attempt to explain this chemical feature, but so far none have been strongly favored by the data. However, they do make different predictions about the prevalence of the alpha-bimodality in Milky Way-mass galaxies. Therefore, we propose to take NIRSpec MSA medium-resolution (R=2700), high-S/N observations of ~130 red giant branch stars in the M31 disk with which we will measure precise metallicity and alpha-abundances (to ~0.03 dex) and search for an alpha-bimodality. These first precise elemental abundances in the M31 disk will double our sample of MW-mass galaxies with which to compare and constraint the models. This will allow us to take a big step forward in our understanding of the most important chemical process at work in our galaxy. In addition, we will use the abundance information, in combination with accurate star formation histories from the PHAT survey, to probe the chemical evolution of the M31 disk in more detail using one-zone chemical evolution models that will allow us to constrain the star formation efficiency, inflow and outflow rates, and initial mass function. This pilot program will demonstrate the utility of NIRSpec for obtaining individual elemental abundances to explore the chemical enrichment of stellar populations lying well beyond the Milky Way in the Local Group.