Which of the following pieces of Matlab code plots a circle of diameter 2, centered at point [radius, 0]?

a.

phi = linspace(0,2*pi,nump); X = cos(phi); Y = sin(phi); X = X+radius; 

b.

phi = linspace(0,2*pi,nump); X = cos(phi); Y = sin(phi)*radius; 

c.

phi = linspace(0,2*pi,nump); X = cos(phi)*radius; Y = sin(phi); 

d.

phi = linspace(0,2*pi,nump); X = cos(phi)*radius; Y = sin(phi)*radius;