The Preamble to the Constitution of India, is

1. A

   part of the Constitution but has no legal effect

   Part but no legal effect. Too weak after Kesavananda / LIC.

2. B

   not a part of the Constitution and has no legal effect either

   Not a part. Berubari was overtaken.

3. C

   a part of the Constitution and has the same legal effect as any other part

   Same legal effect as any article. The Preamble is not independently enforceable like a right.

4. D

   a part of the Constitution but has no legal effect independently of other parts

   A part of the Constitution but no legal effect independently of other parts. Kesavananda: Preamble is part; it aids interpretation, it is not a free-standing writ clause.

Summary. Official key is (d). The Preamble is part of the Constitution. It has no independent, enforceable legal effect apart from the rest of the text; it guides reading of the other parts.