Which of the following statements are TRUE for first-order analyses of NMR spectra (the type of analysis most commonly done). a. Carbon-13, an NMR-active nucleus, has a nuclear spin quantum number of 0.
b. First-order multiplets are symmetrical, and their chemical shift is given by the position of the first peak in the multiplet.
c. The spin-multiplicity of the proton NMR absorption of the methylene group in ethanol-OD is 4. Equivalent protons do not split each other.
d. The difference in absorption frequency is equal to or less than 6 J.