What do street lights typically signify?

Answer: B — 30 mph unless other signs present

Street lights typically signify a speed limit of 30 mph unless other signs indicate otherwise. This is a standard urban speed limit in the UK and applies to built-up areas where street lighting is present. It's important to understand that these rules are in place to enhance safety and make the roads safer for all users, including pedestrians. Other speed limits, such as 20 mph or 40 mph, are indicated by specific signs and are not automatically assumed from the presence of street lights.