If X and Y are any random variables with COV(X,Y) = 0.25, ,then the coefficient of correlation ρ is

A) 1.417
B) 1.190
C) 0.595
D) 0.354

Identify the center and radius of the circle $4x^2+4y^2=1$ .

A) center: (0,0) radius: $\frac{1}{4}$
B) center: (1,1) radius: 4
C) center: (1,1) radius: 2
D) center: (2,2) radius: 1
E) center: (0,0) radius: $\frac{1}{2}$