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.

Question: What was the wind speed from the storm as recorded by vessel? Passage:In early August, an extratropical trough moved off the coast of South Carolina and Georgia, with a stationary front extending from it. A weak low-pressure area began to develop at the southern end of the front just offshore of Jacksonville, Florida. Initially, the storm had an open center of circulation and remained a frontal low as it moved southwestward across Florida, and thus was not considered a fully tropical system at the time. Upon entering the Gulf of Mexico, however, observations indicated that the disturbance developed a closed center of circulation. As a result, the storm was analyzed to have developed into a tropical depression off the western coast of Florida at 1200UTC on August3. At the time, weather reports revealed a definite cyclonic rotation, though the depression had a shallow minimum barometric pressure of 1012.5mbar (hPa; 29.90inHg). Moving west-southwest, the depression steadily intensified and attained tropical storm intensity at 0000UTC on August4. Late that evening, the tropical storm executed a slight northward curve. Strengthening continued into the following day, and ships in the storm's vicinity began to report a much stronger storm than was previously suggested. A ship reported the first gale-force winds associated with the storm at 2100UTC on August4. The S.S. Connecticut observed force11 winds, the strongest wind measurement associated with the storm as recorded by vessel. A minimum pressure of 995mbar (hPa; 29.39inHg) was analyzed for the system at 0600UTC on August5 based on an observation from a nearby ship.
Links: a. Bar (unit) b. Cyclonic rotation c. Beaufort scale d. Gulf of Mexico
c