Correct Response: C. The development of the integrated circuit in the 1950s to replace vacuum tubes led most directly to the development of smaller, faster, and less expensive computers and later devices such as cell phones. While some lasers may be computer controlled, the development of integrated circuits did not lead to less expensive and more powerful lasers (A) or to the development of superconducting materials for electric transmission (B). Similarly, the development of efficient and affordable photovoltaic cells (D) was not significantly related to the development of integrated circuits.
