In this task, you're given a question, a context passage, and four options which are terms from the passage. After reading a passage, you will get a brief understanding of the terms. Your job is to determine by searching and reading further information of which term you can answer the question. Indicate your choice as 'a', 'b', 'c', or 'd'. If you think more than one option is plausible, choose the more probable option to help you answer the question.
Q: Question: Which country today is closest to the Philippine island that was once connected Semporna peninsula? Passage:During the last ice age, the peninsula was connected by an isthmus to the island of Mindanao in the Philippines with the former isthmus included what is now the active volcanic island of Jolo, located at . In the peninsula also located the Skull Hill (Bukit Tengkorak) which consisted largely of numerous isolated hills and mountains, mostly being an extinct volcanoes from the era of Pliocene to Quaternary. Based on survey by Geological Department of Kota Kinabalu, the Skull Hill is said to be an island in its previous form but since the coral limestone terrace of the peninsula have risen from between 100 metres to 130 metres in the past 20,000 years, the hill are not island but a mountainous ridge near the coast. Through a survey on the geothermal presence in the peninsula, the area have a potential to develop geothermal energy as part of the Sabah's renewable energy. The narrow continental shelf fronting the coastal areas of both Dent and Semporna Peninsulas also could be exposed to future tsunamis with the active fault in the eastern coast.
Links: a. Limestone b. Mindanao c. Jolo d. Skull Hill, Malaysia
A:
b