Which one of the following enzymes contains 'Haem' as the prosthetic group?

Histones are enriched with -

Name the class of enzyme that usually catalyze the following reaction :

$$S-G+S^{\#} \rightarrow S+S^{\#}-G$$

Where, G $\rightarrow$ a group other than hydrogen

$$S \rightarrow \text { a substrate }$$

$$S^{\#} \rightarrow \text { another substrate }$$

Which of the following is a nucleotide?