If my new job interview works out just right, I might be able to affor

‘Might’ is used in two different contexts. 1. As a past tense of the modal may, especially in reported speeches that are in past tense. The second context is when the word ' might’ is used in the present tense denoting a lesser probability than the probability of ‘may’. In conditional sentences, it is often used in the main clause in present tense as an alternative to will or is.
Choice B is using the unidiomatic could be able as can or could mean the same as able, meaning the capacity to do. Might does not have that feature of capacity, leaning more on speculation. That is the reason why B and E are considered redundant and are out of the reckoning.
The phrase can be affording in C is again denoting a capacity and in d, the modal ‘should’ implies suggestion or recommendation rather than speculation
A remains with the proper format of the first conditional, in which a present tense 'if clause' is followed up with a present tense main clause.