Which of the following differential equations has `y = c_1e^x + c_2e^(-x)` as the general solution?

Options

A. `(d^2y)/dx^2+y = 0`
B. `((d^2y)/(dx^2)) - y = 0`
C. `((d^2y)/(dx^2)) + 1 = 0`
D. `((d^2y)/(dx^2)) - 1 = 0`