The correct option is B Agrobacterium tumefaciens
Agrobacterium tumefaciens is a soil plant pathogenic bacterium that carries Ti plasmid. It can transfer a particular segment of the tumor-inducing (Ti) plasmid into the nucleus of infected cells. The transferred T-DNA is then integrated into the host genome and transcribed with it. This ability of Agrobacterium tumefaciens to transfer the T-DNA in host genome is explored in genetic engineering to transfer the desired DNA segment, carrying the gene of the interest, into genome of selected organisms. Bacillus coagulans is a lactic-acid producing, endospore forming soil bacteria that is used as probiotics. Clostridium septicum is gram positive, spore forming, obligate anaerobic bacteria that cause gas gangrene and is associated with malignancy.