Why are rotational transitions of little use to a spectroscopist?

Question: Why are rotational transitions of little use to a spectroscopist?
[A].

Because the energy required to induce a rotational transition is so small that it cannot be measured

[B].

Because rotational transitions are extremely rare

[C].

Because, in liquids and solids, spectral lines corresponding to rotational transitions are broadened as the result of molecular collisions and other interactions

[D].

All of the above

Answer: Option C

Explanation:

No answer description available for this question.