When driving in rainy conditions, it's important to:

Increasing the following distance when driving in rainy conditions is essential for safety. Wet roads can significantly reduce traction, which means that stopping distances can be longer than usual. By maintaining a greater distance from the vehicle in front of you, you give yourself more time to react to sudden stops or emergencies. This added cushion allows for safer braking and minimizes the risk of skidding or losing control.

In rainy weather, it's also important to consider how water can create a film on the road, leading to hydroplaning, especially at higher speeds. Therefore, maintaining a longer following distance enhances reaction time and improves overall driving safety.

The other options may pose risks in such conditions. For instance, speeding can increase the likelihood of losing control, while using high beams in rain can cause glare and visibility issues. Lastly, while it's often advised to brake smoothly, completely avoiding brake usage can be impractical and unsafe in many situations. Hence, increasing the following distance is the most effective practice for ensuring safety while driving in the rain.