The correct answer is option 'A' - egg yolk.

Explanation:
Lampbrush chromosomes are large, extended chromosomes that are found in the growing oocytes (immature eggs) of animals. They were first discovered in amphibian oocytes, specifically in the nucleus of the prophase I stage of meiosis.

Key Points:
- Lampbrush chromosomes are characterized by their unique appearance, with two homologous chromosomes that have several chiasmata (crossing-over points) and numerous loops in the chromatin region.
- These chromosomes are named "lampbrush" because they resemble a brush used to clean a lamp chimney.
- The loops on the lampbrush chromosomes contain actively transcribing genes and are involved in the synthesis of RNA molecules.
- The loops are formed due to the unwinding and elongation of the chromatin fibers, allowing for easy access and transcription of the DNA.
- The presence of chiasmata indicates that genetic recombination has occurred between the homologous chromosomes during meiosis, resulting in the exchange of genetic material.
- The lampbrush chromosomes are found in the nucleus of the growing oocytes, which are the immature eggs in the process of development.
- The lampbrush chromosomes play a crucial role in the regulation and expression of genes that are necessary for the proper development of the oocyte and subsequent embryonic development.
- Lampbrush chromosomes are not found in other somatic cells such as skin cells, hair cells, or bean inflorescence. They are specific to the oocytes where they are involved in the preparation of the egg for fertilization and embryonic development.

In conclusion, lampbrush chromosomes are found in the egg yolk, specifically in the growing oocytes, and they are characterized by the presence of two homologous chromosomes with several chiasmata and numerous loops in the chromatin region.