In which of these periods did humans first develop metal tools?
a. paleolithic period
b. neolithic period
c. iron age
d. bronze age

The correct answer is D) the Bronze Age.

In the Bronze Age, humans developed metal tools.

During the Bronze Age, humanity started to use metal to replace stones. Humanity learned to build metal weapons and tools. This era is considered from 3300 to 1200 BC. During the Bronze Age, humanity discovered other important things that helped them to grow, such as the invention of the wheel and some writing alphabets. Humans in Mesopotamia were the ones who experimented with these innovations.

d.summerains, the last one