Due to the gramm-leach-bliley act of 1999
a. allowed european central banks to unite into the european union bank.
b. the us government forbid us commercial banks to own stock of foreign banks and businesses.
c. the us government allowed commercial banks to own stock and sell insurance policies.
d. the us government forbid us commercial banks to own stock of any other business domestic or foreign.

C. the US government allowed commercial banks to own stock and sell insurance policies.

Explanation:

The Gramm-Leach-Bliley Act (GLBA) of 1999 basically repealed or revoked or cancelled the Glass-Steagall Act of 1933. The Glass-Steagall Act of 1933 forbids the commercial banks to own stock and sell insurance policies. So basically by cancelling that Glass-Steagall Act of 1933, the GLBA of 1999 allowed the commercial banks to own stock and sell insurance policies.