In launching the Smart Fortwo car in the United States marketplace, the company took a holistic approach to the marketing mix by $\_\_\_\_\_\_\_\_\_\_.$

a$.$ Offering three different vehicle models, each with a different price point and a different package of standard equipment and options; conducting a $50$ city road tour where the vehicles were displayed and promoted; and using a reservation program to enable customers to move ahead in the sales process as the dealer network was being established.

b$.$ Offering three different vehicle models, each with a different price point and a different package of standard equipment and options; promoted through print ads to make customers aware of the availability of the Smart Fortwo car as the dealer network was being established.

c$.$ Offering only the top$-$of$-$the$-$line Smart car model with the deluxe trim package; conducting a $50$ city road tour where the vehicles were displayed and promoted; and using a reservation program to enable customers to move ahead in the sales process as the dealer network was being established.

d$.$ Offering only the Smart car model with the standard trim package, promoted through heavy television advertising to bring customers into its established dealer network.