A sparse vector is characterized by having most of its elements as zero. The correct examples are:

• B. [1, 0, 0, 0, 0, 0, 0]: This vector contains only one non-zero element, qualifying it as sparse.
• D. [0, 0, 0, 1, 0, 0, 1]: With just two non-zero elements, this vector also meets the criteria for being sparse.