Is the following sentence grammatically correct and why?
(a) "I reckon she doesn't come in on Thursday hearing that"
I was told that since the sentence is in future tense and I am expecting that something won't happen in the future then the sentence should stay in the future tense so I should have said either of the following instead:
(b) "I reckon she won't be coming in on Thursday hearing that"
(c) "I reckon she will not be coming in on Thursday hearing that"
Whilst I agree (b) and (c) are both correct, (a) sounds completely natural in my head and fine to me so I'm not sure what the issue with (a) if there is one.
Thanks in advance.