Quiz: 1D DP Patterns

What is the "adjacent blocking" pattern in 1D DP?

1. A.When taking an element prevents taking its neighbors, leading to $dp[i] = \\max(dp[i-1], dp[i-2] + value[i])$
2. B.Using two arrays instead of one
3. C.Processing the array from both ends simultaneously
4. D.Blocking all elements after position $i$