Direct Fluorescent Antibody (DFA) is one of the methods used for identification of which of the following parasites?

(a) Cryptosporidium parvum and Cyclospora cayetanensis
(b) Giardia intestinalis and Cyclospora cayetanensis
(c) Cyclospora cayetanensis only
(d) Cryptosporidium parvum, Cryptosporidium hominis, and Giardia intestinalis