The Constitution (98th Amendment) Act is related to the options as follows:

Option 1: This amendment is not concerned with empowering the center to levy and appropriate service tax. This falls under the ambit of finance and taxation laws, not constitutional amendments.

Option 2: The Constitution (98th Amendment) Act pertains to the constitution of the National Judicial Commission. It was proposed to make changes to the judicial appointments process in India, aiming to end the collegium system for the appointment of judges and to establish judicial appointments commission.

Option 3: The realignment of electoral constituencies based on the Population Census 2001 doesn`t come under this amendment. Realignments are typically managed by the Election Commission of India in accordance with the Constitution, but not through this specific amendment.

Option 4: Demarcating new boundaries between states is a function that falls under the purview of state reorganization acts. The Constitution (98th Amendment) Act does not deal with this subject.

Therefore, the correct answer is Option 2: The constitution of the National Judicial Commission.