Instructions: This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.
Input: The BBC also introduced Ceefax, the first teletext service, starting in 1974. This service allows BBC viewers to view textual information such as the latest news on their television. CEEFAX has not made a full transition to digital television, instead being replaced by the new interactive BBCi service.
Output:
What kind of service was Ceefax?