In GCM, we define S as S = GHASH(A||0v||C||0u||[len(A)]||[len(C)]). What is u defined as?

• A. 64 ceil[len(A)/128] len(A)
• B. 64 ceil[len(C)/128] len(C)
• C. 128 ceil[len(A)/128] len(A)
• D. 128 ceil[len(C)/128] len(C)