Gerald's full name is Gerald Durrell.

Background Information:
Gerald Durrell was a renowned British naturalist, zookeeper, author, and television presenter. He was born on January 7, 1925, in Jamshedpur, India, and passed away on January 30, 1995, in Jersey, United Kingdom. Gerald Durrell dedicated his life to wildlife conservation and played a crucial role in establishing the Jersey Zoo, which is now known as the Durrell Wildlife Park. He authored numerous books, including "My Family and Other Animals," which is a popular autobiographical work.

Explanation:
Among the options provided, the correct answer is option 'B' - Gerald Durrell. This can be determined by considering the following reasons:

1. Name Consistency: Throughout his life and career, Gerald Durrell was known by his full name, Gerald Durrell. He used this name in his books, interviews, and other professional engagements.

2. Professional Recognition: Gerald Durrell gained worldwide recognition for his work in wildlife conservation and his contributions to the field of zoology. His name is most commonly associated with the full name "Gerald Durrell," emphasizing the importance of his full name in his professional identity.

3. Historical References: When referring to Gerald Durrell in historical records, biographies, and articles, his full name "Gerald Durrell" is consistently used. This further confirms that his full name is indeed Gerald Durrell.

4. Authentic Sources: Trusted and authoritative sources, such as biographies, documentaries, and official websites, refer to him as Gerald Durrell. These sources provide reliable information about his life and achievements, reinforcing the fact that his full name is Gerald Durrell.

In conclusion, based on the name consistency, professional recognition, historical references, and authentic sources, it can be confirmed that Gerald's full name is Gerald Durrell.