I say it’s C ! It sounds about right
Explanation:
company a = 120 + 0.3 × miles
company b = 50 + 0.4 × miles
120 + 0.3 m = 50 + 0.4 m
120 - 50 = 0.1 m
70 = 0.1 m
m = 700 miles
That's not a full sentence. "the glacier" is a phrase, not a sentence.
In any case, to wear an improper expression on your face (to look incredulous when a victory was announced, for example) was itself a punishable offence. There was even a word for it in Newspeak: FACECRIME, it was called.
hope that i helped :)