A. was a beautiful site to look at.
B. was a beautiful sight to look at.
C. is a beautiful sight to look at.
D. is a beautiful sight to look at.
E. is a beautiful site for looking.
Explanation: (C) "Site" is incorrect as it refers to a piece of land, not a structure/statue/memorial. "Sight" is correct for a visually appealing view/object. Since a memorial is generally permanent, the present tense "is" is more appropriate than "was". Hence, "is a beautiful sight to look at".
