Explanation: A NAND gate is a combination of an AND gate followed by a NOT (inverter) gate. An AND gate produces a logic "1" at its output *only* when all of its inputs are logic "1". For any other input combination, an AND gate produces a logic "0". Since a NAND gate inverts the output of an AND gate, it will produce a logic "0" at its output *only* when all of its inputs are logic "1". In all other cases (if at least one input is logic "0"), the AND gate portion would output "0", which the inverter then changes to a logic "1" for the NAND output. Therefore, option D correctly describes this behavior. Option A is incorrect because a NAND gate produces a logic "1" when all inputs are "0". Option B describes an AND gate. Option C is incorrect because if some but not all inputs are "1" (meaning at least one input is "0"), the NAND gate output will be a logic "1".