The effect the use of words with strong positive connotations have on this excerpt is that D.they emphasize the pleasures of riiding a bicycle.
In this excerpt there are no references to the number of people who ride bicycles (answer A) or to a historical development of them (answer B.) There are no references to health benefits either (answer C.)
The excerpt deals with abstract feelings and sensations that result from the pleasure of riding a bicycle, so the correct answer is D.