Instructions: In this task, you are given a context and four options. Each option is a suggested ending for the context. You should read the context and pick the best ending for the context. Please answer with "A", "B", "C", and "D".
Input: [header] How to track a flight on flightaware [title] Visit the flightaware website. [title] Find which flight you need to track. [step] You can track the flights to and from a given airport or by individual airline and flight number. <sep> (A) [substeps] This can be done by accessing the flightaware app on your mobile device. This app is great because if you have an internet connection you can track a lot. (B) Flightaware hosts for free the link to their tracking websites. [substeps] You can also download the flightaware website here: https: // flighta.com/this will tell you a number of different sites where you can track flights to and from. (C) [substeps] If you need to know the airport code, you can check out how to look up airport codes to help. The system will try to search for these airports and airlines as you type, so select from the drop-down box if you spot the right one. (D) [substeps] Click on the button you see through the flightaware tab (toggle right). This will bring out a header-drop box below the boxes listed.
Output:
C