In the preparation of the original hand written Constitution of India, which artist was mainly entrusted with the task of illuminating and decorating the document?

Introduction / Context:
The original Constitution of India is not only a legal document but also a remarkable work of art. It was hand written and beautifully decorated with motifs from Indian culture and history. This question focuses on the artist who was primarily responsible for illuminating and decorating the document. Such cultural details often appear in examinations to test a learner's broader awareness of constitution making.

Given Data / Assumptions:

The question refers to the original hand written Constitution of India.
The key phrase is illuminating the document, which refers to artistic decoration and illustrations.
Four noted artists are listed as options.
It is assumed that the learner is familiar with the role of Shantiniketan artists in this project.

Concept / Approach:
The approach here is straightforward factual recall. Nandalal Bose, a leading artist from Shantiniketan and a pioneer of modern Indian art, was entrusted with the task of decorating and illuminating the original Constitution. He, along with his team of students, created illustrations that appear at the beginning of each part of the document, depicting scenes from Indian history and culture. Although the other artists listed made major contributions to Indian art, they were not primarily responsible for this particular work.

Step-by-Step Solution:
Step 1: Identify that the question is about the artistic decoration of the Constitution, not about drafting or legal work. Step 2: Recall that the original Constitution was hand written by Prem Behari Narain Raizada and artistically decorated at Shantiniketan. Step 3: Remember that Nandalal Bose was the chief artist who supervised and executed the illumination and illustrative work. Step 4: Note that Benode Behari Mukherjee, Abanindranath Tagore and Ramkinkar Baij were also famous artists but are not associated as the principal illuminator of the Constitution. Step 5: From this association, select Nandalal Bose as the correct answer.

Verification / Alternative check:
Verification can be done by consulting standard references on the making of the Constitution. Many articles and books mention that while Prem Behari Narain Raizada hand wrote the text in calligraphy, the decorative borders and illustrations were prepared under the guidance of Nandalal Bose. Photographs of the original pages often credit Nandalal Bose and his team from Shantiniketan. When multiple sources confirm this attribution, it becomes clear that no other option fits the description given in the question.

Why Other Options Are Wrong:
Benode Behari Mukherjee: A respected modernist painter and teacher, but not the principal artist for the Constitution's illumination.
Abanindranath Tagore: A founder of the Bengal school of art, yet he was not tasked with decorating the Constitution document.
Ramkinkar Baij: A renowned sculptor and painter, mainly known for his sculptures at Shantiniketan, not for work on the Constitution.

Common Pitfalls:
A typical pitfall is confusing the roles of different Shantiniketan associated artists and assuming that any famous name from that circle might have done this work. Another mistake is to mix up the contributions of the calligrapher with those of the illustrator. To avoid this, learners should remember a simple pairing: Prem Behari Narain Raizada as the scribe who hand wrote the document and Nandalal Bose as the chief artist who illuminated it. This clear mental association helps answer many related questions with confidence.

Final Answer:
The artist principally entrusted with illuminating and decorating the original hand written Constitution of India was Nandalal Bose.