I will go with C straight away for two reasons
1."but" connects the contradiction better
2. IT makes the whole sentence clearer than any other option does( meaning based approach).
Having said that, can I say "previously is redundant in all options since a past verb already exists in each of the options.
1."but" connects the contradiction better
2. IT makes the whole sentence clearer than any other option does( meaning based approach).
Having said that, can I say "previously is redundant in all options since a past verb already exists in each of the options.