Which pythagorean identity is correct?

A. sin^2(theta)+1=cos^2(theta)

B. tan^2(theta)+1=sec^2(theta)

C. 1-cot^2(theta)=csc^2(theta)

D. 1-cos^2(theta)=tan^2(theta)

Which pythagorean identity is correct?

A. sin^2(theta)+1=cos^2(theta)

B. tan^2(theta)+1=sec^2(theta)

C. 1-cot^2(theta)=csc^2(theta)

D. 1-cos^2(theta)=tan^2(theta)