Fill in the blanks with the most appropriate option:-

Television did not become ______________ until the early 1950s.

common

The most appropriate option to fill in the blanks is common.

The sentence "Television did not become common until the early 1950s" means that television sets were not widely owned by households until the early 1950s. The other options are not appropriate because they do not convey the same meaning.

• The word "intelligent" means having or showing a high degree of intelligence. This does not make sense in the context of the sentence, as television sets are not intelligent.
• The word "usual" means happening or done regularly or normally. This does not make sense in the context of the sentence, as television sets were not commonly owned by households until the early 1950s.
• The word "formal" means done or acting in a serious or proper way. This does not make sense in the context of the sentence, as television sets are not formal objects.