(a) A state trust institution may act as a fiduciary and engage in a trust business at each trust office as permitted by this chapter and at a branch.
(b) A state trust institution may not act as a fiduciary but may otherwise engage in a trust business at a representative trust office as permitted by this chapter.
(c) Notwithstanding subsections (a) and (b) of this section, a state bank or a state trust company may not engage at an out-of-state office in any trust business not permitted for such an office by the host state where the office is located to trust institutions chartered by such state.