The correct options are
A Inability to uptake large insert size
B Inability to express eukaryotic genes efficiently
Plasmids have some limitations when used as vectors. The insert size is very small, upto 6 or 7 kb. When eukaryotic genes are inserted into plasmids, it is not efficiently expressed. To overcome these limitations, scientists have come with many new vectors such as phages, cosmids, BAC and YAC.