Pseudomonas syringae strain Lz4W is a Gram-negative, Antarctic soil species that grows at 0ºC. This strain has been used to determine membrane fluidity when grown at different temperatures

RNA polymerase from E. coli does not function at O°C, whereas in vitro experiments determined that RNA polymerase from Pseudomonas syringae strain Lz4w functions at about 10%-15% of its optimum, which is 370C. Which of the following best explains the difference?

A. The RNA polymerase subunits of the P.syringae strain probably have extra flexibility so that they can move more freely in colder temperatures.
B. There are likely more GC base pairs in the DNA of the genes encoding the RNA polymerase subunits of E.coli so that they are only able to be transcribed at warmer temperatures.
C. There is likely more flexibility in the E.coliRNA polymerase subunits so that they only work at warmer temperatures and not at the colder temperatures of the Antarctic.
D. There are likely more AT base pairs in the DNA of the genes encoding the RNA polymerase subunits of the P syringae strain so that they can be transcribed more easily at colder temperatures.