Complete the statements that follow each of the paragraphs below by choosing the letter of the correct response.

Question

(1) In the 1950s, the introduction of rock ‘n’ roll redefined the concept of popular music. (2) Contributing to the success of popular entertainers like Elvis Presley were the improvements in recorded sound quality that originated with the recording industry. (3) First, came high fidelity, developed by London Records, a subsidiary of Decca. (4) Tape recorders grew out of German experiments during World War II. (5) Ampex Corp. built a high-quality tape recorder, and Minnesota Mining and Manufacturing (3M) perfected the plastic tape. (6) The use of tape meant that recordings could be edited and redefined, something that couldn’t be done on discs. (7) Stereo arrived in 1956, and soon afterward came groups like Marvin Gaye and Martha & the Vandellas with the Motown sounds, which featured the music of African American blues and rock ‘n’ roll artists.

The subject of sentence 4 is
a. Tape recorders.
b. experiments.
c. German.
d. World War II.

Answer 1

a. Tape recorders.