What Would Be The Answer For The Questions In Picture Attached? How Can I Solve Question Like That?

The quot;C NMR spectum of 100% d’-toluene (CD,CD,) was recorded. It shows a non-
binomial septet at 20.4 p.p.m, a singlet at 137.5 p.p.m., and three 1:1:1 triplets at 128.9,
128.0 and 125.2 p.p.m. The structure of toluene is shown below with a numbering scheme.
and has I = 12.
Assume all J coupling can only occur through 1 bond. For D, I = 1. quot;C is 1.1% abundant
CD 3
(a) Which carbon atom gives rise to the signal at 20.4 p.p.m. (1 point)
(b) Why is that signal a septet? (1 point)
(c) Which carbon atom gives rise to the signal at 137.5 p.p.m. (1 point)
(d) Why is that signal a singlet? (1 point)
(e) Why are the remaining signals 1:1:1 triplets? (2 points)
(f) If the compound were 100% H instead of D, what would be the multiplicity of the quot;C
signals? For ‘H, I = 1/2. (3 points)
(g) No coupling between adjacent quot;C atoms is observed, why? (1 point)Science