In the Previous Problem, the Solution of the Eigenvalue Problem $\lambda = n ^ { 2 } , R = r ^ { n } , n = 0,1,2 , \ldots$

In the previous problem, the solution of the eigenvalue problem is

A) $\lambda = n ^ { 2 } , R = r ^ { n } , n = 0,1,2 , \ldots$
B) $\lambda = n , R = r ^ { n } , n = 0,1,2 , \ldots$
C) $\lambda = n , \Theta = c _ { n } \cos ( n \theta ) + d _ { n } \sin ( n \theta ) , n = 0,1,2 , .$
D) $\lambda = n ^ { 2 } , \Theta = d _ { n } \sin ( n \theta ) , n = 1,2,3 , .$
E) $\lambda = n ^ { 2 } , \Theta = c _ { n } \cos ( n \theta ) , n = 0,1,2 , \ldots$