The correct answer is option 'A' - Statutory corporation.

A statutory corporation is a type of public sector undertaking that is established by passing a special law under Parliament. It is a legal entity created by an Act of Parliament or state legislature and has its own powers, functions, and responsibilities defined by the law. These corporations have a separate legal existence from the government and are governed by their own board of directors or governors.

Here is an explanation of each option:

a) Statutory corporation: As mentioned above, a statutory corporation is established by passing a special law under Parliament. It has a separate legal existence and is governed by its own board of directors or governors. Examples of statutory corporations in India include the Reserve Bank of India (RBI), Life Insurance Corporation (LIC), and Oil and Natural Gas Corporation (ONGC).

b) Partnership: A partnership is a form of business organization where two or more individuals come together to carry on a business with a view to making a profit. It is not established by passing a special law under Parliament. Partnerships are governed by the Indian Partnership Act, 1932.

c) Sole proprietorship: A sole proprietorship is a form of business organization where an individual carries on a business on their own. It is the simplest and most common form of business ownership. It is not established by passing a special law under Parliament.

d) Departmental Undertaking: A departmental undertaking is a type of public sector undertaking that is directly controlled and managed by a government department or ministry. It does not have a separate legal existence and is part of the government department. It is not established by passing a special law under Parliament.

In conclusion, a statutory corporation is the correct answer as it is established by passing a special law under Parliament. It has a separate legal existence and is governed by its own board of directors or governors.