Bacteria provide genetic engineers with __ and __

Bacteria provide genetic engineers with _vector_ and _host_.

Vector are vehicles or carriers which are used to carry the gene of interest. They are usually plasmids which are bacterial circular genome which can replicate independently.

Hence bacterial plasmids are used for the insertion of gene of interest and its transfer to the host cell.

As plasmids is taken from the bacteria, so mostly bacteria is used as the host for the gene of interest.

gold i'm pretty sure i might be wrong

chert is a sedimentary rock composed of microcrystalline or cryptocrystalline silica. with this little bit of information, you can come to the conclusion that your answer is c.  

explanation: