Answer : 1. "Roger Bacon"
Explanation :

Gunpowder is commonly credited to Chinese alchemists, and it is believed to have been discovered accidentally in the 9th century during experiments to find an elixir of immortality. While the exact inventor remains unclear, the use of gunpowder for military purposes spread during the subsequent centuries.

The option (A) Roger Bacon is also historically associated with gunpowder. Roger Bacon, an English philosopher and Franciscan friar in the 13th century, wrote about the composition of gunpowder, although it is debated whether he was the actual inventor.

Gunpowder is a mixture of saltpeter (potassium nitrate), charcoal, and sulfur. Its invention had a profound impact on military technology and warfare throughout history.