The reviews research conducted using animal subjects.

a. nih
b. iacuc
c. irb
d. nimh

b. IACUC

Explanation:

First of all, let's determine the wrong variants;

1) NIMH: The National Institute of Mental Health (NIMH)

2) IRB: Institutional review board or independent ethics committee

3) NIH: National Institutes of Health

The true option is IACUC: Institutional Animal Care and Use Committee

IACUC is USA based committee which deals with law applications on the animal research. There are several local IACUC  and they usually review locally the protocols and then conduct the estimations and evaluations. The IACUC was based on Animal Welfare Act in 1986. The IACUC must have minimum 5 members which includes chief executor/ officer.And the evaluations held by them at least once 6 months.

an informal structure in a bureaucracy would be something like so-called "office politics". where there's a formal structure set up for the organization, but then an informal subculture as well that has a way of organizing the bureaucracy further. this can be positive because it sets up an added degree of organization, albeit informal, within the bureaucracy.