You will be given a definition of a task first, then some input of the task.
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: Which county that I-24 goes through has the highest population? Passage:I-24 continues southeast through the rapidly growing suburbs of Nashville, and crosses into Rutherford County near the city of LaVergne, where there are three exits. Beginning at this point, I-24 is relatively straight and flat for most of its distance through Middle Tennessee. The straightest stretch of highway in Tennessee is located on I-24 between Lavergne and eastern Murfreesboro, where the route is perfectly straight for about fifteen miles, although the median widens and narrows. Four miles later is an interchange with SR 102, which connects to Smyrna and the Nissan Motor Manufacturing Plant. Another four miles later is an interchange with Interstate 840, the outer southern beltway around Nashville, and I-24 enters Murfreesboro, the largest suburb of Nashville. In Murfreesboro, I-24 has interchanges with SR 96 (which connects of Franklin), SR 99 (New Salem Highway), and US 231 (which connects to Lebanon and Shelbyville), respectively, and at the final Murfreesboro exit (US 231), the HOV lane designation ends, and I-24 narrows to six lanes and then four lanes a short distance later. Three miles later is an interchange with the Joe B. Jackson Parkway, which serves as an outer beltway around southeast Murfreesboro. I-24 then enters a more rural area, and at exit 97 has an interchange with SR 64, which connects to Shelbyville. I-24 then curves to the south, then the east, briefly enters Bedford County, and then Coffee County. At exit 105 is an interchange with US 41, and five miles later I-24 enters Manchester, where it has interchanges with SR 53, SR 55, and US 41, respectively. I-24 continues through a rural, largely agricultural area where it crosses into Grundy County and has an interchange with US 64 and SR 50.
Links: a. Rutherford County, Tennessee b. Tennessee State Route 53 c. Nissan d. Lebanon, Tennessee
Output:
a