The correct answer is B. Dashing.
A rakish person is typically described as being stylish, carefree, and confident. They are often seen as being charming and attractive. Dashing is a synonym for rakish, as it also describes someone who is stylish and confident. Frivolous, aggressive, and childish are not synonyms for rakish, as they do not accurately describe the characteristics of a rakish person.
Frivolous is an adjective that means “not serious or important; not worth much thought or attention.” Aggressive is an adjective that means “ready or likely to attack or confront; forceful.” Childish is an adjective that means “of, relating to, or characteristic of a child.”
A rakish person is not necessarily frivolous, aggressive, or childish. They may be stylish and confident, but they are also likely to be carefree and charming.