Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the option that best fits each of the numbered blanks from 18 to 22.

Self-driving cars are rapidly becoming a reality in today's world. Major companies like Tesla and Google ___(1)___. Tesla's autopilot system, for instance, was first introduced in 2015 and has since been refined to enhance vehicle safety and navigation. These cars rely on sophisticated AI systems to function autonomously, allowing them to perform tasks such as braking, accelerating, and steering without human input. ___(2)___. It can also predict traffic movements, and navigate roads efficiently.
The technology behind self-driving cars is still developing, but it has already begun to revolutionize the way we think about transportation. Companies that create autonomous vehicles focus on building reliable systems ___(3)___. Legal frameworks around the world are also evolving to regulate the use of these cars. Many experts say that self-driving cars are believed to help reduce accidents, improve efficiency and decrease fuel consumption by optimizing driving efficiency.
However, the challenges are not just technological. ___(4)___. People from different backgrounds and driving experiences need to feel confident in the safety of self-driving cars before they can be widely adopted. Nonetheless, as advancements continue, it seems inevitable that autonomous vehicles will play a critical role in shaping the future of transportation, ___(5)___.