In __________ transmissions can be four or six speeds.rear wheel drivefront wheel drivefour wheel drivepassenger carsCVT

The correct answer to fill in the blank is "passenger cars."

Passenger cars can have various types of transmission options, including those with four or six-speed automatic or manual transmissions. Each of these options is designed to deliver the necessary power and efficiency for everyday driving. The term "CVT" (Continuously Variable Transmission) refers to a different type of transmission system that smoothly changes through an infinite number of effective gear ratios, rather than using a fixed number of speeds like four or six. However, when referring broadly to vehicles equipped with multiple discrete gear speeds, passenger cars are the category that includes vehicles with four or six-speed transmission systems.