Instructions: 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.
Input: Question: What year was the club that Threlfall played for in 1987 found in? Passage:Threfall played for Cumberland in 1987, making a single appearance in the Minor Counties Championship against Cambridgeshire and a single appearance in the MCCA Knockout Trophy against Cheshire. In 1988, Threfall played Second XI cricket for Sussex, with him also making his first-class debut for the county in that season against Somerset at the Recreation Ground, Bath. He played regularly for the Sussex Second XI, but would only make two further first-class appearances for the county, against the touring Sri Lankans in 1990 and Cambridge University in 1991. He never batted in his three first-class appearances, but with the ball he took 7 wickets at an average of 18.57, with best figures of 3/45. He also made a single List A appearance for the county against the touring Zimbabweans in 1990. He ended Sussex's innings of 233/8 unbeaten on 17, while in the Zimbabweans innings he took figures of 3/40 from 10 overs, with Sussex winning by 95 runs. He continued to play for the Sussex Second XI until 1994.
 Links: a. Cumberland County Cricket Club b. Sussex County Cricket Club c. Somerset County Cricket Club d. First-class cricket
Output:
a