Answer:
A. a mutation that means Ras cannot hydrolyze GTP to GDP
Explanation:
Since Ras will remain in its active Ras-GTP form, Ras will continue to tell the cell to divide even when it is not correct to do so. This likely happens in cancer cells because of mutations in the Ras gene producing a Ras protein which can no longer be in its "off state" Ras-GDP.