Here, your A.P. is 7000, 7600 ....
Now, You need to calculate the number at 7th place,
We have: a = 7600, d = 7600 - 7000 = 600, n = 7
a(n) = a + (n-1)d
a(7) = 7600 + (7-1) 600
a(7) = 7600 + 3600
a(7) = 11200 feet
In short, Your Answer would be Option C
Hope this helps!