Answer:
Well, I can't quite determine if you mean for this to be a trick question or if you are serious.
I say that because technically speaking, A and C show future tense, while B and D show past tense.
Of all the options, A is the best one to represent the present tense. While it certainly <u><em>can</em></u> represent the present tense, it does a much better job at representing the future tense. Yes, really. Let me give you some other examples so you'll see what I mean.....
Explanation:
Today, I'm leaving for Paris on the 4:00 p.m. flight. = future tense
Today, the army is sending me to boot camp. = future tense
.......................
I should add....
If you were to say: "Today, I'm babysitting my nephew." --- <u><em>and you said it at the moment that you are in the house next to your nephew</em></u> -- then, THAT would be present tense.
In this example, we're talking about an action that is happening at the moment of speaking unlike option A above which refers to an action that hasn't happened yet.
Have you got it??