A quick way to solve this is to recall what each silkworm disease is known for and match features one by one. Pebrine is caused by the spore forming parasite Nosema bombycis, historically grouped under protozoa, confirming (B), and it is a genuine disease of silkworm, confirming (A). Its hallmark diagnostic sign is the appearance of small black speckles on the larval skin, which gives the disease its name and confirms (D). A larva releasing a foul smell right after death is instead a sign of flacherie, a bacterial infection, so (C) does not belong with pebrine and must be dropped. \[\boxed{\text{(A), (B) and (D) only}}\]