Starch is a mixture of two components, a water-soluble component amylose (15-20%) and a water-insoluble component amylopectin (80-85%). The aqueous solution of amylose gives a blue colour with iodine solution due to the formation of:

A. amylose iodide

B. amylose iodate

C. inclusion complex

D. amylose tetraiodide complex

In the crystal lattice of the host molecule amylose, there are tunnel-like spaces. These tunnels are just the right size to accommodate guest molecules such as iodine, leading to the formation of an external compound known as an inclusion complex.

A key property of this complex is that the blue color appears when iodine is included, but it disappears on heating and reappears upon cooling.

• Option A (Amylose–iodine): This forms a deep blue-purple solution, which does not match the description in the question.
• Option B (Amylose–iodate): This compound cannot be formed with amylose or amylopectin, so it is not the answer.
• Option D (Amylose–tetraiodide complex): Involves a hydrophobic channel, which again does not match the context of the question.

Therefore, the correct answer is: C. Inclusion Complex.