Validate that values in column A are the same And data in column D are increasing

Hello everyone,

This should be easy, but it is the data in column D that I can't figure out:

I have data like this: I need to verify that If Column A is the same (for example, 100007) that the data in column B is increasing for each row. For example, Column C would say Yes for C2 through C5, but will say No for C6 through C8.
A B
1 2
1 3
1 4
1 5
2 2
2 1
2 2

Thanks