might be in trouble

[azz]

a. When I was young, if people behaved that way, they might be arrested.
b. When I was young, if people behaved that way, they might have been arrested.

c. When I was young, if people behaved that way, they might be in trouble.
d. When I was young, if people behaved that way, they might have been in trouble.

Are all of these sentences grammatically correct?

What is the difference in the meanings of (a) and (b)?
What is the difference in the meanings of (c) and (d)?

Many thanks.

[Alan]

Regarding (b and (d): see previous reply.

In this case, (a) and (c) are possible but infelicitous, owing to the normally present understanding of 'might' (despite its origin as a past tense-form). Better would be, e.g. 'they were sometimes arrested'.