The answer is "D. Chemistry for explosives".
Artisans and scholars made essential innovative advances amid the Tang and Song dynasty. Among the most imperative developments were movable type and gunpowder. With movable type, a printer could mastermind squares of individual characters in an edge to make up a page for printing. Beforehand, printers had cut the expressions of an entire page into one substantial square. The development
of gunpowder, in time, prompted the production of explosive weapons, for example, bombs, projectiles, little rockets, and guns.
Other imperative innovations of this period incorporate porcelain, the mechanical clock, paper cash, and the utilization of the attractive compass for cruising.
