If $$P$$ represents radiation pressure, $$E$$ represents radiation energy striking per unit area per unit time and $$c$$ represents speed of light then the possible values of non-zero integers $$x$$, $$y$$ and $$z$$ such that $$P^xE^yc^z$$ is dimensionless, may be

A

$$x = 1,\ y = 1,\ z = 1$$

B

$$x = -1,\ y = 1,\ z = 1$$

C

$$x = 1,\ y = -1,\ z = 1$$

D

$$x = 1,\ y = 1,\ z = -1$$