Congress leaves it to the Bureau of Prisons to oversee the promulgation of detailed regulations in areas under the agency's juris¬diction. This is:

a. divine right.
b. the delegation of legislative powers.
c. gap-filling power.
d. unconstitutional conduct.

Delegation of power

Explanation:

In U.S constitutional law the delegation of power by any of the three branches of the government to  an independent agency or another branch is called delegation of power. It is not an authorisation or permission, it is simply transfer of power. The power and  juridical nature of delegates are exactly those that belonged to the delegant.

The delegation of power violated the concept of separation of powers hence it can be said to be unconstitutional. But the US Congress has created various agencies and delegated its authorities to enforce regulations. e.g Securities and Exchange commission(1934) and The Federal Election commission(1974), It has also delegated to the department of commerce to conduct decennial census.

on june 23, 1972, the president signed title ix of the education amendments of 1972, 20 u.s.c. into law. title ix is a comprehensive federal law that prohibits discrimination on the basis of sex in any federally funded education program or activity.