Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.
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Question: Pittosporum viridulatum is a critically endangered species of plant in the Pittosporaceae family.

Answer: What is the conservation status of Pittosporum viridulatum?


Question: Riociguat (Adempas(®)), a soluble guanylate cyclase stimulator, is a new, first-in-class drug approved for the treatment of patients with chronic thromboembolic pulmonary hypertension (CTEPH) [inoperable or persistent/recurrent following surgery] or pulmonary arterial hypertension (PAH). It has been designated an orphan medicine by the European Medicines Agency and the US FDA. This article reviews the available pharmacological properties of oral riociguat and its clinical efficacy and tolerability in adults with CTEPH or PAH. Riociguat is effective and well tolerated in patients with inoperable CTEPH or persistent/recurrent CTEPH following pulmonary endarterectomy, and in patients with PAH. It has a positive result on exercise capacity and pulmonary haemodynamics, and improves WHO functional class. Most adverse events can be attributed to the vasodilatory mechanism of riociguat; however, there is a potential for serious bleeding and fetal harm, and riociguat use is contraindicated in pregnant patients. Pulmonary endarterectomy remains the first treatment of choice for CTEPH, as it is potentially curative. Head-to-head trials comparing riociguat with the approved phosphodiesterase type 5 inhibitors in patients with PAH would be of value for the placement of riociguat in the management of this disease. Riociguat is a promising addition to the treatment options for patients with CTEPH or PAH.

Answer: What is generic name of drug Adempas?


Question: The 80-string koto (or hachijugen) was an invention of Japanese composer Michio Miyagi which appeared In 1923.

Answer:
By whom was 80-string koto discovered?