The Preamble to the Constitution of India serves as the guiding light and sets the principles followed by the Indian Constitution, hence it is considered as a part of the Constitution.

But let`s understand each option:

Option 1 suggests the Preamble is a part of the constitution but has no legal effect, which is incorrect because though not enforceable by the judiciary independently, it aids the judicial interpretation of other parts of the Constitution.

Option 2 is incorrect, the Preamble is indeed a part of the Constitution as affirmed by the Supreme Court of India.

Option 3 suggests the Preamble has the same legal effect as any other part of the Constitution. This is not entirely correct because independent of other parts, it may not produce legal effects.

Option 4 is the most accurate here as it suggests the Preamble is a part of the Constitution, but cannot independently produce legal effects. The Preamble indeed plays a decisive role in the interpretation of statutes and also in the adjudication of the Constitutionality of any law.