They are all OK.
Can I make a suggestion here? It's clear that you're teaching fairly basic English, in other words, if there are subtle differences between the meaning of sentences, your students don't need to know them. Don't give them lots of almost identical options. In this case, I'd give them (a) since it's got fewest words and is also the most commonly used.
If they are confident with (a), then (b) to (d) are not going to confuse them, and if (e) to (h) come up in class, you can tell them they mean the same.
Another suggestion is to start your own 'Help for Japanese people teaching English' thread (I assume you're Japanese!), which you and hopefully in future other teachers such as yourself can ask all your questions.