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: How many races did Hornish participate in during his first full time year? Passage:Hornish moved to Penske's NASCAR program part-time in the Xfinity Series (then known as the Busch Series) during the 2006 season, and began driving part-time in the Sprint Cup Series (then known as the Nextel Cup Series) in 2007. He raced full-time in the Sprint Cup Series the following year, struggling at first, with eight top-ten finishes over his first three seasons and a top points placing of 28th (in 2009). Hornish returned part-time to the Xfinity Series (then known as the Nationwide Series) in 2011, winning one race. He drove full-time in the series the following year, finishing fourth in points. In 2012 Hornish replaced A. J. Allmendinger (suspended by NASCAR for failing a drug test) in Penske's No. 22 car midway through the season, earning one top-five finish. The following year he returned to the Nationwide Series, winning one race and earning 16 top-five and 24 top-ten finishes to place second in points (three behind series champion Austin Dillon). Hornish drove part-time for Joe Gibbs Racing in an eight-race 2014 season, with one win and four top-five finishes. He returned to the Cup Series in 2015 with Richard Petty Motorsports, scoring three top-tens and finishing 26th in points. He returned part-time to the Xfinity Series in 2016, winning a race for JGR and finishing sixth or better in all three races he entered for Richard Childress Racing. In 2017, he returned to Penske's Xfinity program for a three-race schedule in the No. 22.
Links: a. 2008 NASCAR Sprint Cup Series b. Joe Gibbs Racing c. 2014 NASCAR Nationwide Series d. Joe Gibbs Racing
Output:
a