Suppose the output response of a linear system is expressed as y(s) = 1/(s2 + 4). Use Laplace transform tables to find a symbolic expression for the time response of this system, y(t).

A. y(t) = sin(2t)
B. y(t) = cos(2t)
C. y(t) = sin(4t)
D. y(t) = cos(4t)