You will typically need a gap of about four seconds to . a. change lanes b. cross a four-lane intersection c. turn left

B. cross a four-lane intersection

Explanation:

When driving, it is important to properly calculate the time that it takes you to perform several different actions. For example, when you need to cross a four-lane intersection, this will usually take you about four seconds. Knowing how much time you need to perform a particular action will allow you to do so safely and efficiently.