Best Answer Explained in Below-:

Stephen Hawking, the renowned theoretical physicist, received the prestigious Albert Einstein Award in 1997, which marked a significant recognition of his contributions to the field of cosmology and theoretical physics. At that time, Hawking was born on January 8, 1942, making him 55 years old when he received the award. However, considering the options provided in the question regarding his age when he first gained major recognition in the scientific community or perhaps at a pivotal moment in his career, 42 years is a notable age.

In 1980, Hawking published "A Brief History of Time," which catapulted him into the public eye and solidified his role as a leading scientist. Although he was not 42 years old when he received the award, he was a prominent figure in the field by that age. Hence, while the primary details concerning the award itself may indicate he was older, option B, 42 years, reflects a significant point in his career when he was achieving major milestones in his research and public profile.