The correct answer is D. All of the above.
Political opposition is a major challenge in implementing tax reforms. Tax reforms often involve changes to the tax code that benefit some groups and harm others. This can lead to opposition from those who are negatively affected by the reforms.
Administrative complexities are another challenge in implementing tax reforms. Tax reforms can often be complex and difficult to implement. This can lead to delays and errors in the implementation of the reforms.
Loss of revenue in the short term is also a challenge in implementing tax reforms. Tax reforms often involve cuts in taxes. This can lead to a loss of revenue in the short term. However, tax reforms can also lead to economic growth and increased tax revenue in the long term.
In conclusion, political opposition, administrative complexities, and loss of revenue in the short term are all challenges in implementing tax reforms.