Read the following sentence. considered by many the first self-propelled vehicle, leonardo da vinci sketched it in 1478. how can this sentence be improved to be more effective? a. the sentence is best as it is written. b. leonardo da vinci sketched what is considered by many the first self-propelled vehicle in 1478. c. leonardo da vinci sketched the first self-propelled vehicle, which is what many consider the first. d. in 1478, leonardo da vinci sketched what many consider the first self-propelled vehicle.