How can help he explain this problem.

Each cell in the table below represents a 4-byte block. The value in one or more first object is 12 bytes or 3 blocks). The total heap size is 80 bytes or 20 blocks. 4 4 adjacent cells (yellow background) represents the size of that object (for example the 12 4 16 8 Based on the current allocation state, what is the external fragmentation of this heap? 16 bytes or 4 blocks 20 bytes or 5 blocks 12 bytes or 3 blocks 24 bytes or 6 blocks