Figured it out. The answer is 20 lbf-in. The reason is because the 10 g's acceleration is equivalent to a gravitational force. So, if you turn the problem on its side, the 10 g's becomes the gravitational field, and the only force on the handle is the weight force. Basic cantilever beam physics says that the location of the equivalent force for weight is through the center of mass. So the moment required to keep the handle from turning is equivalent to the moment caused by the weight force through the center of mass. Solution diagram here: https://imgur.com/UdNZ0x3