The sum of the terms of the infinite geometric series 1, 0.86, 0.86², 0.86³, ..., is closest to which of the following numbers?

A) B0
B) 1.86
C) 7.14
D) 0.54
E) 116.28

The common ratio is 0.86, and the first term is 1, so the sum can be calculated using the formula $S = \frac{a_1}{1-r}$, where $a_1$ is the first term and $r$ is the common ratio.

Plugging in, we get:

$S = \frac{1}{1-0.86} = \frac{1}{0.14} = \frac{100}{14} = \frac{50}{7} \approx 7.14$

Therefore, the sum is closest to $\boxed{\textbf{(C) }7.14}$.