(D) Mesocarp

The edible portion of a mango is the mesocarp, which is the fleshy and pulpy middle layer of the fruit. The outer skin (exocarp) is not typically consumed, and the inner seed (endocarp) is also not eaten. The mesocarp is the part that is juicy, sweet, and commonly enjoyed in various culinary applications, such as eating the fruit fresh, making juices, or incorporating it into salads and desserts.

(D) Jonas Salk

The polio vaccine was developed by Dr. Jonas Salk. He and his team conducted extensive research in the 1950s, leading to the development of the inactivated polio vaccine (IPV), which became widely used for the prevention of polio. The vaccine was a significant breakthrough in medical science and played a crucial role in the global effort to eradicate polio.