Given a math problem with context and a question and 5 answer choices, the task is to provide the correct answer choice based on the problem. You must choose one of the given answer choices by letter: a, b, c, d, or e; anything else is invalid.

Problem: in traveling from a dormitory to a certain city, a student went 1 / 3 of the way by foot, 3 / 5 of the way by bus, and the remaining 2 kilometers by car. what is the distance, in kilometers, from the dormitory to the city ?
Options: a. 30, b. 45, c. 60, d. 90, e. 120
a

Problem: the sector of a circle has radius of 24 cm and central angle 135 o. find its perimeter ?
Options: a. 91.5 cm, b. 11.5 cm, c. 104.6 cm, d. 92.5 cm, e. 99.5 cm
c

Problem: a horse is tethered to one corner of a rectangular grassy field 42 m by 26 m with a rope 16 m long. over how much area of the field can it graze ?
Options: a. 154 cm 2, b. 308 m 2, c. 201 m 2, d. 205 m 2, e. none of these

c