✅ The correct answer is option D.
The transistor, which essentially is a solid-state electronic switch, replaced the much less suitable vacuum tube. Because the transistor consumed significantly less power, a computer system built with transistors was much smaller, faster and more efficient than a computer system built with vacuum tubes.
✅ The correct answer is option C.
The first message ever sent over what is now called the Internet took place at 10:30PM on October 29, 1969. Back then, the Department of Defense called it ARPAnet (Advanced Research Projects Agency network).