Question

gallantly means : in a heroic or brave manner cautiously and with foresight quickly and without warning a manner lacking seriousness

Explanation:

The word "gallantly" is an adverb. By referring to a dictionary or using language knowledge, "gallant" has meanings related to bravery and heroism. "Gallantly" would then mean in a heroic or brave manner. The other options: "cautiously and with foresight" is more related to words like "prudently"; "quickly and without warning" is like "suddenly"; "a manner lacking seriousness" is like "flippantly".

Answer:

in a heroic or brave manner