Solve 2x2 + 12x − 14 = 0 by completing the square. (2 points) A. 2(x + 6)2 = 26; x = −6 + square root 13 , x = −6 − square root 13
B. 2(x + 6)2 = 20; x = −6 + square root 20 , x = −6 − square root 20
C. 2(x + 3)2 = 32; x = 1, x = −7
D. 2(x + 3)2 = 32; x = 13, x = 19
Can someone help me out please?

You are standing next to a really big circular lake. you want to measure the diameter of the lake, but you don't want to have to swim across with a measuring tape! you decide to walk around the perimeter of the lake and measure its circumference, and find that it's 400\pi\text{ m}400? m. what is the diameter dd of the lake?