What are the correct structural descriptions for $\mathbf{M}$ and $\mathbf{N}$ ?

• A

  $\mathbf{M}$ is $\beta$-D-(+)-glucopyranose and $\mathbf{N}$ is $\beta$-D-(-)-fructofuranose
• B

  $\mathbf{M}$ is $\alpha$-D-(+)-glucopyranose and $\mathbf{N}$ is $\alpha$-D-(-)-fructofuranose
• C

  $\mathbf{M}$ is $\alpha$-D-(+)-glucofuranose and $\mathbf{N}$ is $\beta$-D-(-)-fructopyranose
• Correct answer
  D

  $\mathbf{M}$ is $\alpha$-D-(+)-glucopyranose and $\mathbf{N}$ is $\beta$-D-(-)-fructofuranose

Hence, the correct answer is option: 'D'.