Answer:
letter D
Explanation:
The controlled railroad crossings have red lights and warning signs with railway gates. But if none of those items are present, then it is an uncontrolled railroad crossing.
Uncontrolled railroad crossing warning signs include; D; None of the above
There are two main types of railroad crossings namely;
A Controlled railroad crossing has signs such as warning signs, red lights and railway gates.
However, in uncontrolled railroad crossing, the signs don't include any of the ones listed for controlled railroad crossing signs but instead will have no signs, no signals and no gates.
Looking at the options, A, B and C represent controlled railroad crossing signs and so the correct answer in none represents uncontrolled railroad crossing signs.
Read more about railroad crossings at; https://brainly.com/question/4360017
