Choice "A" is correct. There can be no more than 35 unaccredited investors under a Rule 506 offering. Note that the 35 unaccredited investors must be sophisticated investors.
Choice "d" is incorrect. Although there can be no more than 35 unaccredited investors under Rule 506, there can be any number of accredited investors.Choice "b" is incorrect. There can be up to 35 sophisticated unaccredited investors under a Rule 506 offering.Choice "c" is incorrect. There can be any number of accredited investors.