Final answer:
True. Modern computers can only operate in binary at their most fundamental level because transistors can only be "on" or "off". Binary code is used to represent data in digital circuits.
Step-by-step explanation:
True. Modern computers can only operate in binary at their most fundamental level because transistors, which are the basis of a CPU, can only be "on" or "off". Transistors behave like an on-off switch, where they are either fully open or fully closed. Binary code, which consists of ones and zeroes, is used to represent data in digital circuits found in computers.