Teacher:This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.
Teacher: Now, understand the problem? Solve this instance: Passage: The aftermath of World War II saw an explosion in the discovery of new classes of antibacterial drugs including the cephalosporins (developed by Eli Lilly based on the seminal work of Giuseppe Brotzu and Edward Abraham), streptomycin (discovered during a Merck-funded research program in Selman Waksman's laboratory), the tetracyclines (discovered at Lederle Laboratories, now a part of Pfizer), erythromycin (discovered at Eli Lilly and Co.) and their extension to an increasingly wide range of bacterial pathogens. Streptomycin, discovered during a Merck-funded research program in Selman Waksman's laboratory at Rutgers in 1943, became the first effective treatment for tuberculosis. At the time of its discovery, sanitoriums for the isolation of tuberculosis-infected people were an ubiquitous feature of cities in developed countries, with 50% dying within 5 years of admission.
Student:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
When was the first effective treatment for Streptomycin discovered?