Single/multi-select question: Does the sentence "Because the production of high-quality semiconductor materials was still decades away, Lilienfeld's solid-state amplifier ideas would not have found practical use in the 1920s and 1930s, even if such a device had been built." provide a valid answer to the question "Who filed a patent for the field-effect transistor?"
Available options:
(a). yes;
(b). no;
(b).