Okay, let's tackle this question about Haemophilus species and satellitism. First, I need to recall what satellitism means. From what I remember, satellitism is when a bacteria requires another organism to grow, like needing factors produced by Staphylococcus aureus. Haemophilus species often need factors like X (hemin) and V (NAD), so maybe some species can grow around staph, while others can't.

The question asks which species does NOT show satellitism. The options aren't listed, but common Haemophilus species include H. influenzae, H. parainfluenzae, H. ducreyi, and H. aphrophilus. I think H. influenzae is the classic one that shows satellitism because it needs V and X factors, which staph can provide. H. parainfluenzae might also show it. H. ducreyi, which causes chancroid, I'm not sure. Maybe it doesn't require those factors. H. aphrophilus, involved in endocarditis, might not need them either. Wait, I need to confirm which species don't require those factors. Satellitism is the growth around staph colonies, so the species that don't need V/X factors wouldn't show this. So the answer would be the species that don't require those factors. Let me check: H. influenzae requires both X and V, so it shows satellitism. H. parainfluenzae requires V but not X, so maybe it shows partial satellitism. H. ducreyi doesn't require those factors, so no satellitism. H. aphrophilus also doesn't require them. So the answer is either H. ducreyi or H. aphrophilus. But the question is about which one does NOT show satellitism. If the options include H. ducreyi, that's the correct answer. Let me make sure. Yes, H. ducreyi is known not to require X or V factors, so it doesn't show satellitism. Therefore, the answer is H. ducreyi.

**Core Concept**
Satellitism is a growth phenomenon where *Haemophilus* species depend on exogenous factors (X and V) produced by other bacteria like *Staphylococcus aureus*. Species requiring these factors form colonies near staph colonies; those that don’t require them grow independently.

**Why the Correct Answer is Right**
*Haemophilus ducreyi*, the causative agent of chancroid, does **not** require X or V factors for growth. It lacks the ability to synthesize nicotinamide adenine dinucleotide (V factor) and hemin (X factor), but unlike other *Haemophilus* species, it can grow without these dependencies, thus showing **no satellitism**.

**Why Each Wrong Option is Incorrect**
**Option A: *Haemophilus influenzae*** – Requires both X and V factors, showing strong satellitism.
**Option B: *Haemophilus parainfluenzae*** – Requires V factor but can grow with staph-produced X factor, showing partial satellitism

✓ Correct Answer: D. H.ducreyi