In What Way Do Banks,trust Companies,stockbrokerages,and Insurance Companies Share a Commonality

In what way do banks,trust companies,stockbrokerages,and insurance companies share a commonality with one another?

A) Each institution ensured stability within the financial services industry.
B) Liberalized ownership rules are traditionally applied to the four sectors.
C) Each was subject to the same regulations affecting the financial services industry.
D) The traditional financial services industry contained the four distinct sectors.