4. Speed should be reduced below the posted speed limit for which of the following reasons? a. driver is driving in unfavorable weather conditions b. driver is approaching and crossing an intersection c. both of the above

## Step 1<br />This problem is about understanding the rules of the road, specifically when it is necessary to reduce speed below the posted speed limit. The options provided are:<br />a. The driver is driving in unfavorable weather conditions<br />b. The driver is approaching and crossing an intersection<br />c. Both of the above<br /><br />## Step 2<br />Option a suggests that speed should be reduced when the driver is driving in unfavorable weather conditions. This is a common rule as poor weather conditions can make it difficult to see the road ahead, which can lead to accidents.<br /><br />## Step 3<br />Option b suggests that speed should be reduced when the driver is approaching and crossing an intersection. This is also a common rule as intersections can be dangerous due to the potential for other vehicles to cross the path of the driver.<br /><br />## Step 4<br />Option c suggests that both of the above reasons are valid for reducing speed below the posted limit. This is the correct answer as both unfavorable weather conditions and approaching intersections are valid reasons for reducing speed.