Chapter 15, Problem 51P

Which of the diethylbenzene isomers (ortho, meta, or para) corresponds to each set of 13C NMR spectral data?

[A] ${}^{13}\text{C}\text{NMR}\text{signals:}\text{16,}\text{29,}\text{125,}\text{127}\text{.5,}\text{128}\text{.4,}\text{and}\text{144}\text{ppm}$

[B] ${}^{13}\text{C}\text{NMR}\text{signals:}\text{15,}\text{26,}\text{126,}\text{128,}\text{and}\text{142}\text{ppm}$

[C] ${}^{13}\text{C}\text{NMR}\text{signals:}\text{16,}\text{29,}\text{128,}\text{and}\text{141}\text{ppm}$