James Stillman is an investment adviser representative with Rock, Feller, and Standard (RFS), a covered adviser with its principal office in State O. Stillman works out of an office in State P and has 4 retail clients there. In addition, Stillman has 25 retail clients in State D, 6 retail clients in State M, and 1 retail client in State O. Stillman would be required to register as an investment adviser representative in

Stillman should register as an investment adviser representative in state P.

Explanation:

Investment adviser representatives (IARs) must necessarily register in the state that they work in. In this case, Rock, Feller, and Standard (RFS) must be registered in all the states where it has offices functioning, but Stillman only needs to register in the state where his office is. If Stillman worked half year in state P and the other half in state M, then he would need to register in both states. But since this is not the case, then registering in state P should be enough.