Methanococcus, Thermococcus and Methanobacterium exemplify

Options :

1. bacteria that contain a cytoskeleton and ribosomes

2. bacteria whose DNA is relaxed or positively supercoiled but which have a cytoskeleton as well as mitochondria

3. archaebacteria that lack any histones resembling those found in eukaryotes but whose DNA is negatively supercoiled

4. archaebacteria that contain protein homologous to eukaryotic core histones