Answer:
C
Step-by-step explanation:
A, B and D are all only a few digits long and can be expressed as the ratio of two integers, where at least one is even:
A = -6/16 = -3/8, so it's rational
B = 7.0398 = 35199/5000, so it's rational
D = 6,907 = 13814/2, therefore rational
C, on the other hand is irrational.
If we simplify the surd √8, we get 2√2. The 2's on the top and bottom can now cancel out, giving us √2, which is irrational. [There's a proof but it's kinda long].
