Rare cutter is

1. Rare cutters are restriction enzymes that recognize longer and less frequent sequences in DNA.
- These enzymes cut DNA at specific recognition sites, usually 6 to 8 base pairs long.

2. Eco R I is a rare cutter.
- It recognizes the specific sequence 5'-GAATTC-3', which occurs less frequently in the genome compared to shorter recognition sequences.

3. Rare cutters are useful in genome mapping and cloning.
- They generate larger DNA fragments, making them ideal for analyzing larger genomic regions.

4. Options like Hae III and Alu I are frequent cutters.
- They recognize shorter sequences and cut more frequently, producing smaller fragments.

5. Option D is correct as Eco R I is classified as a rare cutter due to its longer recognition sequence.