Question

Which of the following inventions of the 1950s made other inventions possible?

Answer 1

The UNIVAC was not the first computer ever built. A host of companies, including Eckert-Mauchly, Remington Rand, IBM, and others, all were developing computers for commercial applications at the same time.  the UNIVAC I was the first computer to be widely used for commercial purposes – 46 machines were built, for about $1 million each.

Answer 2

You didn't give us choices, but I suspect the answer you're looking for is:

the transistor

John Bardeen, Walter Brattain, and William Shockley were awarded the Nobel Prize in Physics in 1956 for the invention of the transistor. (It might be noted, however, that there was some friction between Schockley and the other two members of the Bell Labs' team, Brattain and Bardeen.) A 2007 article in Computerworld magazine calls the transistor "the single most important invention of the 20th century." In addition to its early uses, making transistor radios and car radios possible, transistors have become the key component to all types of electronic devices. The transistor also functioned as "the building block for the processor," according to Computerworld.