What kind of question is please be careful.

Imperative.

Explanation:

There are four types of comments/questions.

1. Interrogative. an interrogative means that you're trying to ask a question. It always ends with a question mark.

2. Imperative. An imperative comment is when you're telling someone what to do or telling them how to do something.

3. Declarative. A declarative comment is when you just comment regularly. Nothing applies to this.

4. Exclamatory. An exclamatory comment is when you're trying to show excitement or a strong emotion

postards have pictures on them, these pictures are things that may never be seen again. the pictures are a part of our history that shows things. because of this many collectors would pay a lot of money for them.

i read on google they "offer a glimpse into the past"

hope this : )

a. is the correct answer